Free Software Voice Over IP Solutions?

Shisha asks: "I'm looking for some Voice over IP solution for Unix (Linux, and Solaris in particular). I want to call friends in Prague from the UK. Is there any way how to make the phone call go over the net?" I know there are programs like CCFAudio, Ethernet Phone, FreeWebFone and Speak Freely, however I haven't used any of these programs so I can't say to how well they perform. Have any readers out there tried any of these or have other VoIP solutions that they use that deserve mention?

Comments

Is there such a thing as GnuPhonella?

[Anonymous Coward]

Not the nasty mayonnaise stuff, what I'm visualizing is a distributed club of VOIP users who serve as volunteer gateways *INTO* their local phone system. I.e.,

Caller gets on computer,

which is (or gets on) internet via local 'phone/DSL/cable/intranet-gateway/etc.,

caller starts GnuPhonella, enters international phone number

GnuPhonella locates a DestinationCityLocalArea GnuPhonella node that isn't busy, and negotiates service,

Destination node dials *OUT* into DestinationCityLocalArea,

where someone asnwers by *ORDINARY* phone, and

conversation ensues. (FAX could be done similarly).

Does this exist (I mean for cheap h/w with GPL s/w)? Note that it requires simultaneous internet connection and POTS voice dialout at the destination, to get to an ordinary phone in that area, but with non-phone internet connections becoming common (especially in businesses) that should be less and less of an obstacle.

What cards can dial voice connections for your computer? Any voice modem? Or is there more to it? Special wire to audio card from modem like CD wire? Can you have both?

GnuPhonella nodes could be identified first by their international phone prefix paths, so knowing the number you want to dial could do an automatic search for the a node at that area.

BTW, what would be the legal difference between a group doing this as (a) internal between branches of a business, (b) internal to a human family, (c) a private club, (d) an informal group of friends, or (e) an anonymous public association?

Re:Is there such a thing as GnuPhonella?

[don.g]

You mean an audio version of tpc.int? It does what you want, for faxes. (with an e-mail interface, too!)

Re:Is there such a thing as GnuPhonella?

[Anonymous Coward]

If I recall correctly, the Free World Dialup project was doing something like this starting in 1995. They don't seem to be, any more, but their page is still up at http://www.pulver.com/fwd/, with some links on the issue. Go up to www.pulver.com for some more.

Re:Is there such a thing as GnuPhonella?

[renehollan]

I've had similar ideas, but haven't taken them anywhere yet. Check out http://www.hollan.org/netconnect.html if you're interested

Re:Is there such a thing as GnuPhonella?

[jfernie]

You have a great idea. Something like this should not be hard to get working on the software side. Ideas like this exist already in hardware.

I've set up VOIP solution for a customer using Clarent technology. Very effective boxes. We have one in each of their offices and a carrier-class (i.e., much bigger) unit at the telco switch. The boxes plug in to the keysystem at the customer site and all they have to do is dial a 7 to get an "internal" line (dial a "9" to get a local Bell line). The user dials a number and these boxes use their routing tables to decide which box they need to call. A user at location A wants to make a call in city B, and they have an office there, so all he has to do is dial a 7, area code, and the Clarent boxes place this call through the unit in city B. If the area code doesn't have a box in it, then it default-routes to the big box at the telco switch, onto the national Long Distance backbone, and they get discounted LD because they don't have to go through any Bell.

Now, Clarent has *expensive* boxes so that won't work well on small scales. Also, the routing information is stored in a central database which all the satellite units talk to. That brings up the single point-of-failure problem.

IANAL, but it seems like the legal issues are moot. Each node would be paying for local phone service, and paying for internet service. Do what you want with it. The only problem I see is countries which have government monopolies on phone networks. They often have anti-competitive laws in place but this would be an example of tech getting the jump on laws. I doubt any country actually has legislation outlawing anonymous VOIP distributed networks.

The hardware is the only thing left. Most real modems don't interface with sound cards in hardware, nor do they have a "clear channel" mode to let me stuff whatever audio I want on the line. At least, I've never seen one. Some of the weirder winmodems do use the sound card for the tone generator. Those are mostly on all-in-one integrated mobo's, and my intuition tells me they aren't *nix friendly. The hardware would also have to deal with international CO lines which have different tones and electrical characteristics. If anyone out there has an idea for the hardware problem, I'd be interested in working on or starting a GNU project for this. I'd love free international calls.

Re:Offtopic=6, Funny=7, Total=13

[Stone Portman, CGI]

Offtopic=6, Funny=9, Total=13

GO MODERATORS!!!!

Legislation passed (HR 1291) bad for IP Telephony

[Lonesmurf]

Recent legislation (May 16, 2000) has recently been passed and is now actually on the books. This new law is an amendment to the United States Code and it may lead to taxation of IP telephony.

Here is the bill with the amendment.

The bill is supposed to not allow the taxation of internet services, but at the last minute due to pressure from the TelCo companies, a new paragraph was added to the end making IP Telephony taxable.

What do you guys think?

For more information:
Internet Rally against HR1291
A Wired.com article about this legislation.
A ZDNet article.

Rami James
Pixel Pusher
--

Originally from the Usenet Oracle

[Meerkat]

This was originally created by a devotee of the Usenet (now Internet) Oracle. No idea who the author was.

The original text can be found here.

Meerkat.

Re:VON

[tmatysik]

umm... here in New Zealand, we had Telecom privatised about 10 years ago. Before then, we had a state-of-the-art telephone system.... now, the system is badly run down and totally obsolete. Only about half of the lines in rural areas are even capable of sustaining a 14.4k modem connection.

Telecom NZ has a contract with the government... the "Kiwishare agreement"... that forces them to keep local phone calls free. They've been using every possible opportunity to try and get around it... the 0867 scheme is a good example, forcing data calls to go through a seperate network so they could charge 2c a minute after 10 hours, except for calls that went to ISPs with 0867-prefixed numbers (so they could then degrade service to all ISPs except their own, XTRA, maybe...)

then there's also the time they decided to make all current prepaid phone cards obsolete with no refunds.... 19 million dollars worth of them. They didn't get to do that, thank god.

They pull something like 12 billion dollars a year out of this country. For a country as small as New Zealand, that's one hell of a lot. Overall, I'd be happier if Telescum were still owned by the government.

Voice over IP Flawed Archtitecturally

[trey]

Ok, basically TCP packets drop all the time and computers put them back together. You are trained from birth to pick up even the smallest flaw, and you will find the conversation annoying - since the application stream is impossible to detect for content based reassembly. We are doing real time, perfect quality sound transmission every morning when we say hello to ea. other. VoIP on IPv4 - sounds like junk no matter how technically perfect ... at least right now.

Re:Voice over IP Flawed Archtitecturally

[Cramer]

1. trained from birth to pick up even the smallest flaw

I'd have to differ with you there. How many times per week did you study "listening for flaws"? Humans are interesting creatures, however, we are surprizingly insensitive to many things. If you listen intently for specific flaws, then you are likely to hear them -- even when they aren't there. You might be surprised by the amount of damage to a digital audio signal that you cannot hear.

I wouldn't say VoIP is "junk". It's not as perfect as conventional telephony, but for the price, you cannot beat it. I've setup and used VoIP and I found it to be on par with the quality of most cellular phones. The round-trip delay is alot higher and there are flitters of drops as packets get lost or too far out of sequence. In my case, the call was effectively zipping around the planet -- my desk in NC to CA via standard IP into GRIC's private IP network to a partner in Germany and back into the PSTN to a desk in London. There was about a half second delay (I was monitoring the call on my end.) Yes, it was far worse than me dialing London directly from my desk, but at 2.97 CENTS per minute, VoIP beat the crap out of convention telephony.

MozillaPhone?

[gwalla]

How long do you think it'll be before someone writes a VoIP module for Mozilla? Now that would kick ass.

---
Zardoz has spoken!

Free VoIP/Videoconferencing Solution

[fuzzybunny]

Maybe this is what you're looking for:

http://ee.lbl.gov/vat

Re:VON

[petros]

So the telco there was privatized without opening the market to competition? If this is the case, this is not what I'm advocating... A private monopoly might or might not be a bit better from a public monopoly, but it's still a monopoly. What you need is competition, and effective regulation from the government so that the telcos can make money but can't screw the consumer. I admit it's not easy to maintain this balance, but it has been done with varying degrees of success in various places in the world. I'm most familiar with telecom in Canada, and it's a perfect example where there is really affordable communications of very high quality for every taste (from landlines to high speed internet access), through competition and generally good regulation.

Interoperable? Compatable?

[egghat]

How compatible are the million solutions mentioned before?

Can I use speak freely with Nautilius? Can I use RAT with Voxilla?

TIA for your shared knowledge!

Re:Windows For Telepaths

[dalroth5]

Ignore the anonymous coward: it's just that.
Your writing is good: do more.

Re:Local calls

[David Roundy]

Actually, you'd have to be pretty careful even in the US. I don't know how you'd distinguish local toll calls from true local calls, as they both have the same area code (although local toll calls are to people who live further away).

And local toll calls are usually more expensive than long distance calls because the local phone company has a monopoly (and to be fair, they also have government restrictions on their base rate, which they have to recoup somehow).

why is this funny? I'm in Israel calling Philly!!!

[firewort]

What makes this funny, VoIP is good for international calls (Israel to Philly)

outside the US, we pay per minute on a local call... international is killing me!

Internet phones a pain...

[Ambien]

Internet phone can be a lot more trouble then it's worth. It took me days before I got mine working. Also once you do get it working there's still about a 1 - 1 1/2 second sound delay no matter what speed connection you have. At least that was my experiance since I tried it cable modem to cable modem.

what i did..

[dermond]

there is a lot going on in the linux telephony world. a good source for information is linuxtelephony.org.

i was implementing a VoIP solution for a company a few weeks ago where linux based kiosk terminals where euquiped with phones that should be able to make VoIP calls to a central callcenter including video. i looked at the existing software. H323 seems to be the way of the futurere and there are already H323 based solutions on the way. openh323.org. even thought they where not stable enought for my needs yet. but at least the demo appication (voxialla) was able to interoperate with the M$ netmeeting shit. video transmition with H263 codec (for low bandwith) is also on the way. for my solution i decided to use quicknet telephony cards (it greatly enhances the telphony experience if you have a real phone connected to your computer which can also ring and is independent of the sound card). those have a DSP on board which does voice compression accourding to the most important standads. it has a GPL'ed kernel driver. (the only downside is the DSP code itself is not open but that is not that much of a problem).

i decided to just adopt the demo code that came with the quicknet cards for my appolication since it was more stable then the H323 things. (it is easy since the compression is already done on the card). for the video thing i used a parallel netscape server push with 1 picture every 3 or 4 sekunds 160x120 (about 2k Byte) in size). greetings mond.

Re:what i did..

[nexus9k]

Quicknet Technologies definitely has some cool products.

Check out the Internet Phone Jack, which is a full-duplex audio card designed specifically to carry your voice over the Internet and the Internet Line Jack, which connects your local phone lines to an IP network.

And yes, there's full Linux support.

And... no -- I don't work there. I just think it's a very cool product. :)

while the phone co. holds me hostage

[firewort]

International calls are impossible-- try calling from zimbabwe to the states, try calling from israel to the states, rates are sky-high!

As it is, to use VoIP I have to pay for the local call to my ISP... why should I pay double digits USD for a 5 minute call over regular billing!

Gnome-o-Phone

[Ed Avis]

What about Gnome-o-Phone? Also, a Freshmeat search might be helpful...

Re:VON

[norton_I]

Email is stealing as well. How dare you deprive the USPS of their hard earned postage?

Using free software is theft because if you want software, you should pay for it.

Sheesh. VoIP is only stealing if you are stealing the bandwidth in the first place.

Re:VON

[petros]

Public network infrastructure, power, phone, net, everything should be nationalized. End of story.

You might want to say this to the people in all the countries that used to have government owned monopolies running all telecom. I'm sure they'll inform you that they were paying a lot more than you are for phone service, and that in many cases it wasn't as good. They'll also tell you that after the market was opened up in their country, and the national telcos privatized, cost has gone down and quality has gone up. Strange, eh? I guess that national telecom monopolies are indeed a superior idea, but we just haven't seen any proper implementations to date. Kind of like communism, I guess.

Local calls, packet queuing, linmodems

[Cato]

Nice idea, as long as local calls are free of charge - currently true in most of US, but certainly not in Europe (though some countries may have extra-cost packages for unmetered local calls).

I'd like to see such gateways for deaf people, calling out or in at 300 baud to/from textphones using old, cheap modems - the idea is to network deaf people (who use textphones a lot - think keyboard plus very old modem in one package) into the huge world of Internet instant messaging (and maybe WAP and SMS messaging for mobile phones).

As for VoIP - check out the Linux-DiffServ project, its EF (Expedited Forwarding) per-hop behaviour (jargon for a special packet queuing mechanism) is very good at doing VoIP, which needs very low latency and fairly low loss. In other words, your Linux router/firewall, or even desktop, should always send a VoIP (EF marked) packet first, even if other packets are also queued.

The other thing needed is link-level packet fragmentation - Cisco call this LFI, which is proprietary, while the IETF calls it ISSLOW - the idea is that your large (1500 byte) FTP packet should be 'preemptible', i.e. it is actually sent as many small layer 2 fragments (not IP fragments), so the VoIP packet (probably only one layer 2 fragment) can sneak in very quickly after the current short FTP fragment. Compressed RTP headers a la Cisco would be very useful - cuts down IP/UDP/RTP headers to about 2-3 bytes. These tricks are most relevant to low speed lines (modems now, mobile phones in the medium term) However, both of these tricks require your ISP to cooperate, so not so useful for Gnuphonella.

For one major possible latency improvement, see the John Carmack posting a while back about low-latency Linmodem drivers - these will also be important for VoIP without special hardware.

Re:Local calls, packet queuing, linmodems

[carton]

It would be a lot easier to respond to your posting if you had included some hyperlinks. I am interested in your pet theories, but I don't have time to go searching for each one by hand.

The problem with fair queueing on modems is that the internal buffer inside the modem is usually quite large (on the order of 10 packets), and this buffer isn't subject to queueing. AFAIK the buffer must stay inside the modem for reasons of Tradition and V.42b. All real-time/fair queueing algorithms must muck with the output queue. For real network cards rather than modems, this means NIC drivers can reorder packets inside the FIFO onboard the network card. Each hardware NIC driver must have fair queueing support to deliver a good implementation. Therefore, it will never happen with traditional modems. You will have to buy a new modem, which may not exist yet.

I think you are talking about fair queueing w.r.t. ``Linux-diffserv'' because diffserv is the name of an IETF fair queueing working-group.

There is a lot of research on fair queueing. It deals with issues like the one you discuss, voice packets pre-empting large FTP packets. However, all the papers I've read are a much more advanced discussion than knee-jerk reactions like introducing another complexity into the protocol stack. They typically start with a GPS model in which each packet is 1 bit long, and then generalize the results for discrete packets. The ordering of the packets is actually a lot more interesting than their size.

This research was basically completed about five years ago with Hui Zhang's HFSC algorithm, which is implemented in the ALTQ package for *BSD. ALTQ is part of the KAME IPv6 stack that the three BSD's are importing into their trees and tracking as it evolves.

The relevant aspect of these algorithms is their ability to allocate bandwidth and latency separately and predictably. A high-bandwidth, high-latency FTP connection can share the same packet-switched link with a low-bandwith, low-latency VoIP connection. This is what ``real-time scheduling'' means. Although usually those words refer to CPU scheduling, the ideas and algorithms involved are similar if not identical.

This software is a real Computer Science answer to the age-old phone company allegations that only circuit-switched networks will ever reliably carry bounded-latency multimedia streams. It is not new, although it may be new to Linux or to popular use. If implemented on the whole Internet, it's basically proven that these algorithms can guarantee a clean, low-delay connection with no dropouts.

There are other papers about how to distribute some of the processing so these algorithms can scale to the core backbone, as well as stuff about extending them to wireless networks. Some of this research may be ongoing.

Anyone know which VoIP stacks work with IETF's diffserv ideas or RSVP?

Re:Local calls, packet queuing, linmodems

[Cato]

Actually they are not just my pet theories :) Every maker of VoIP-capable routers will use something along the lines of DiffServ.

Searching on google.com for linux diffserv and ISSLOW provides reasonable links, btw - the actual links of interest are http://lrcwww.epfl.ch/linux-diffserv/, and for ISSLOW, http://www.ietf.org/rfc/rfc2688.txt and http://www.ietf.org/html.charters/issll-charter.ht ml.

The Carmack contribution is on slashdot.org, search for carmack and modem. Or see www.linmodems.org and http://directory.google.com/Top/Computers/Software /Operating_Systems/Linux/Hardware_Suppor t/Modems/

For general info on QoS and links to DiffServ info, see www.qosforum.com.

Actually fair queuing is only one DiffServ PHB (per hop behavior, i.e. queuing technique basically) - DiffServ is an architecture that specifies where and how traffic should be classified, marked, shaped, metered, shaped and queued/dropped. FQ is only one technique in the diffserv toolkit, and is currently not being standardised within DiffServ. Diffserv also standardises the format and meaning of the TOS byte, and defines some standard codepoints (e.g. EF for low latency, low loss).

FQ algorithms are quite nice, since you can reduce latency without just allocating extra bandwidth to a class/flow, but they are relatively costly to implement on routers, which may be why Cisco implements only a class-based form of FQ within its higher end routers. Although Juniper seems to do more granular stuff... I tend to focus on algorithms that have been implemented and turned on in widely deployed routers (since I work for a policy-based network management company, Orchestream), but there's a lot of research out there, as you point out. Implemented mechanisms tend to be quite simplistic, e.g. PQ-CBWFQ from Cisco is a bandwidth limited priority queue layered on top of a class-based weighted fair queuing setup (the PQ carries VoIP typically).

Linux's diffserv effort is really just a layer on top of the quite impressive set of queuing mechanisms built into the 2.2 kernel. Probably at least as complete as KAME, and able to support RSVP as well as DiffServ apps.

As for modems - you are right about the buffering problem, which is why Carmack et al are looking at how you write a mostly-software modem that can be loaded into the Linux kernel in order to (a) reduce overall latency vs hard modems and (b) allow priority or fair queuing perhaps.

Whatever mechanisms you introduce are protocol transparent typically - PQ, WFQ, WRED, HFSC, etc all simply re-order, delay or drop packets. They introduce extra complexity into the host and router IP stacks, but are normally at the interface queue level.

Apps don't necessarily have to be changed to support DiffServ - just use appropriate linux/BSD commands to classify the appropriate traffic. RSVP does provide more functionality but normally requires the app to be changed somewhat. I don't know specific linux apps that support RSVP, I would guess only the ones that were used when originally testing the RSVP stac (vic and vat??).

State of Linux Audio Drivers

[seppy]

I've tried conferencing with Speak Freely and it worked OK, except for the fact that I cannot speak and listen at the same time due to the state of sound drivers under linux. I use the OSS drivers and have a yamaha opl3-sa2 and it would appear that there is no full duplex support for my card. Until you have full duplex drivers as the norm and not the exception it would seem to me that audio & video conferencing is doomed to suck under linux. Am I doing something wrong? Is alsa better in this respect? What is the current state of full duplex audio drivers for linux? I can't wait for the day that I can do voice recognition and still play mp3's or listen to a real audio stream. Are there any packages that work around this problem with full duplex?

RW is Cross Platform (PC + Mac)

[Bloo]

A couple of months ago, the Roger MacWilco Mac Alpha was released. It allows PC and Mac users to communicate with each other on the same RW channel. Just FYI, In October of 99, Roger Wilco merged with HearMe (formerly MPath Interactive). In addition to Roger Wilco, HearMe has several free voice products available now (currently all PC though)

Wimba -- www.wimba.com

[Anonymous Coward]

Wimba is a great asyncronous audio application, rated #1 overall by the independent Java Applet Rating Service judges at www.jars.com.

http://www.wimba.com

Wimba lets you send voice and text messages, with email notification, to individual email addresses, and semi-private and public forums.

Supported platforms include unix and windows. It uses a couple of TCP ports listed on the FAQ, so it may not work behind most firewalls.

Re:Windows and Linux VoIP.

[Rhys Dyfrgi]

One tip, and I think it may apply to most software packages. Tell the software that your connection is a little slower then it
actually is. This may degrade the voice quality a little, but it gets rid of that annoying lag.

Not so. I discovered the other day that Linux RealPlayer7 (and, I assume, other versions) will not use all the bandwidth available if you tell it you have a slower connection. It now thinks I have a T1 (I have cable), since none of the other settings made it use all the available bandwidth. Sure, it'll screw up some bandwidth negotiations, but few streams will want more than I have anyways.

I wouldn't be surprised if other apps have this `feature' as well.
---

Re:VON

[Cramer]

Competition is generally a good thing. However, there has to be a stable, profitable market and demand. If no one is willing to pay the cost of a service at the level of quality they demand, then competition cannot help; a company cannot run at an operating loss for extended periods -- this is where government traditionally steps in. (see also: dairy subsities)

Do you think anyone would be eager to step up and sell ISP services if people were only willing to pay 2$/month for dialup (56k modem and ISDN), 5$/month for DSL, or 7$/month for T3-like cable modem service? There's no way to make money like that. The "free ISPs" of the world are still very new to the scene and may very well fail hideously -- but then, they make money from advertising, not by selling connectivity. (If banner ads have taught us anything, it's that people become blind to them and even spend money on software to filter them out. How many banner ads are in the web pages you see everyday? How many do you notice? How many do you actually click on?)

CCFaudio

[mdh]

As one of the authors of CCFaudio I can make a few comments. IMHO, CCFaudio offers the best performance. It has a nice gui and gui operations do not interfere with sound quality as they do for most of the others. It works well on Sparc Solaris, Intel Linux, and SGI Irix. It should work well on any pthreads based unix.

It also offers good multiuser conferencing. Most of the others don't.

On the negative side, it is not compatible with any other iphone. Most iphones offer some standard protocols--vat being the first and there are some newer ones. It wouldn't be very hard to add compatibility modes to CCFaudio, but the funding ran out (it was developed as part of an NSF funded project). Feel free to hack.

CCFaudio can be used with CCFringer which provides a gui for establishing connections. It only works if the other user is using it, too, of course. It hasn't been widely tested.

Hope that helps,

Re:VON

[tmatysik]

oh, the market's open to competition, alright. Telecom has about the same level of competition from Clear as Microsoft has from IBM/OS2Warp. The only area where Clear has any sort of hold, is long-distance calls. The problem is, when it was privatised, the market was totally deregulated, and Telescum owns all of the lines.

At the moment, we're just hoping that the new wideband wireless bandwidth the government is selling, will encourage competition within the next few years.

Try Nautilus

[mikenet]

Nautilus is a free(and open-source) voice over IP(or serial connection) program that focuses on encryption, however you can turn it off if you don't want it, or if you run into truble with export laws. I have ran it many times with it's 2.4Kbit codec, and it sounds much better that anything else I have ever heard over 56k modems. Since your only using 2.4kbit/s, if you are using it over bad links, it can easily resend data and have plenty of bandwith still left over.

It will run under DOS,Windows,and many types of Unix

Get it here

Re:Try Nautilus

[acarey]

Sounds cool, but what if you're outside the US?

Some info

[Money__]

LinuxTelephony
openphone.org
Packetizer.com
SpeakFreely.org
Voxilla.org
___

Re:Some info

[Anonymous Coward]

www.dialpad.com You use your computer to all any phone anywhare no cost

Re:Some info

[Penrif]

"I'm looking for some Voice over IP solution for Unix (Linux, and Solaris in particular)."

Dialpad requires Windows, BTW. Oh, and it only works computer-phone in the US. "anywhare" hardly applies.

Re:Some info

[JoostFaassen]

HotTelephone

Commercial as hell, and works with some active-x component (ngrep ready folks ?) so it's windows only, but the soundquality is astonishing and the delay is less than half a second(tried with isdn)... You can call everyone in the US or Europe. Ok, so it's not voice-over-ip in the way your asking for, but there might be a few folks out there interested in this...

This post is powered by caffeine

OpenH323

[GTM]

There's an interesting solution I heard of recently : OpenH323 is an open source implementation of the H323 specifications (it covers several audio and video conferencing protocols and codecs).

Re:OpenH323

[dpk]

OpenH323 is an incredible project. It is more stable than most commercial grade H323 stacks when it comes to audio (H323 includes video also - think NetMeeting). Its really strong points are:

• Crossplatform - runs on Windows and *nix (Im not sure about Max or Bez et al)
• It has been tested and interoperates with more H323 stacks than you knew existed - Radware, Cisco...
• Free Software - which is the point of this article, right?

There are some problems with the H323 specification in general though. For example:

• Very complex ... just take a look at the codebase
• Control data is transmitted in binary form - most widely used protocols are based on ASCII (FTP, HTTP, SMTP)
• It uses a port assignment process which is virtually impossible to use through a NAT firewall.

There are of course many options in the VoIP world right now - SIP is a protocol that works to simplify the processes of the H323 stack. As far as I know, there are a few different implementations of SIP and none of them work very well with each other. You can read more about it here.

A friend of mine has written some very good articles about Linux and Internet Telephony:

Linux Journal Article
SVLUG Presentation

I personally think that the best solution right now in terms of interoperability, quality and Free-as-in-speech-ness is OpenH323 with OpenPhone. Our company uses a combination of Quicknet PhoneJACKs, OpenH323, and a few CIPE VPN tunnels to connect people from CA to Texas to Australia at their Linux boxes using real-live ringing phones - at essentially no cost. Quality is very very close to a typical old-guard phone call, even from San Francisco to Sydney over the Internet, _and_ encrypted. Blows my mind whenever I use this stuff. The Quicknet cards have GPL'd drivers and are in the current kernel tree. They seem to add a ton of power to the call by offloading alot of the work to hardware DSPs.

Re:OpenH323

[Sun]

• Control data is transmitted in binary form - most widely used protocols are based on ASCII (FTP, HTTP, SMTP)

Now, I am not sure about that, but I am pretty sure. HTTP and FTP, both, allow 8 bit connections. With SMTP the protocol didn't want to assure that, so 7bits are recommended (but not required). Once 7bits are used, the overhead isn't significantly bigger than the 7/8 bandwith limitation you impose.

Do correct me if I'm wrong.

Another phone...

[leibnitz27]

I've used the originally named 'phone' *g*
It works pretty well, but requires a central
'name'server... (yes, you could remove that, it's
GPL).

Author: David Ashley
http://www.xdr.com/dash
Program name: Phone
Program Homepage: http://www.linuxmotors.com/phone

Windows For Telepaths

[Stone Portman, CGI]

Windows For Telepaths

You open the box labeled "Windows TP", carefully extracting the pouch labeled "License Agreement". You examine the contents of the pouch, finding an inflatable beanie bearing the Windows logo rather than the familiar 3.5" diskette package. You inflate the beanie, insert two "C"-size batteries (not included), and carefully place it on your head. You press the Start button.

Immediately, the image of an hourglass comes to your mind. You find yourself trapped; unable to move anything in your body save your eyes. After an indeterminable delay, you regain control of your senses. You are suddenly compelled to speak your name and business affiliation. You then retrieve your Windows TP package and chant the Product-ID number.

Suddenly you see the words "Windows is detecting new hardware" flash before your eyes. You crash to the floor, writhing in agony. You feel every muscle in your body contract and retract in turn. Your mind is filled with the image of a blue inchworm, creeping slowly across a grey field. The creature finally reaches the edge of its domain, and your seizure ceases. You take a moment to regain your composure, and you are reminded of your high school anatomy course as a complete listing of every organ in your body appears before your eyes. You browse the list for a moment, and utter the phrase "OK". After a short delay, you hear the sound of a trumpet echo through the recesses of your mind.

You find yourself in a large, barren space. You look around, and discover images labeled "My Brain", "Recycle Bin, and "Set up the Microsoft Network". You feel compelled to utter the word "Start", after which a list of options floods your mind. Weary from the detection phase, you utter the word "Shut down". You close your eyes, and blackness surrounds you. You feel yourself start to drift into sleep. Your peace is interrupted, however, as a bright orange light invades your nothingness. "It's now safe to shut down your mind".

You drift into unconsciousness, and sleep for several hours. When you awaken, you are frozen in place as you see clouds and blue cycling colors. After a short eternity, the familiar "My Brain" icon reappears in your mind. But something is terribly wrong; you can feel it in your gut. Just outside the range of primary vision, you can sense something lurking about you on all four sides.

You slowly look up, and see the word "Safe Mode" glaring back at you. You back away slowly, swivel your head, and there it is, behind you as well. Your heartbeat quickened and you are terrified as you turn to your left and your right and it meets you there as well, its cold, heartless glare filling your soul with despair.

Quickly, you summon Control Panel, System, Device Manager. You feel yourself frantically gasping for air as you run through the list of installed devices. You come upon "Respiratory System" and are horrified to see a black exclamation point on a yellow field next to the entry "Lungs". You close your eyes and utter the word "Properties". On the closed curtains of your eyelids, you see your life flashing before your eyes.

You force yourself to concentrate on your situation, attempting to discover which system devices are in conflict, when suddenly your entire body seizes up in pain. You lose all sense of reality. You are floating through the clouds as you hear a voice echo through your mind: "This program has performed an illegal operation and will be terminated." You start to black out and suddenly you remember your situation. You stare in horror at your blue extremities, knowing that, without oxygen, you will not last much longer. With all the consciousness you can muster, you force yourself... To reboot.

You awaken in a place that is dark, but familiar. A solitary white prompt on a black field greets you. You look behind you and see the wreckage of the operating system that nearly spelled your demise. "Cannot find a file that may be needed to run Windows". You turn around to face the prompt, and a wide grin comes across your face. You take a deep breath and revel in the life-giving atmosphere. You laugh as you utter the words, "DELTREE WINDOWS".

Suddenly you find yourself on the floor of your home. You find the charred remains of the Windows TP beanie littering the floor. You carefully gather them up, stack them neatly on an altar, and burn them, promising yourself never to risk your life with Microsoft again. You bury the ashes, knowing that your life is again in order.

Re:Windows For Telepaths

[sanemind]

Severly offtopic, but nonthesless extremely funny!

Perhaps slashdot could have a "jokes" section or some sort of wholly general message board to prevent such, [but then again, I would probably never read it], eiye! slashboard spam...

Look at the hardware and possibly reconsider

[mu_cow]

The software mentioned are all possibilities. However, in my experience using computers to send audio across the net has lots of problems.

Unless your soundcard and software can do full duplex (mix incoming and outgoing sounds) the conversation can get very confusing. Unless you are used to saying "over" at the end of a sentence I suppose.

To those saying that you are cheap, I understand. I can ring USA for 3p/min from the UK, but Prague would be 19p/min.

By all means give it a go. However, you may find that you are better sticking to email and instant messaging between expensive calls.

Robust Audio Tool

[Felipe Hoffa]

Get & try RAT: Robust Audio Tool at http://www-mice.cs.ucl.ac.uk/multimedia/software/r at/ It's open source, and they have builds for major platforms (FreeBSD, HP-UX, IRIX, Linux, NetBSD, Solaris, SunOS, and Windows 95/NT). Au regards, Fh

Windows and Linux VoIP.

[www.sorehands.com]

I have used buddyphone on a WindowsNT system through IPCHAINs.

One tip, and I think it may apply to most software packages. Tell the software that your connection is a little slower then it actually is. This may degrade the voice quality a little, but it gets rid of that annoying lag.

I tried this on a PII-266 under WinNT 4.0 SP5 though a firewall using RH 6.0 on a Pentium Overdrive 83 system on a Cable Modem.

I'd like to some software that will let me use OS/2 and Linux to talk to people I know that run Windoze.

Roger Wilco

[magic]

I use Roger Wilco under Win32. This is not available for Linux currently, is is a technology that is related to your question and may interest you (as well as interesting to other readers).

Roger Wilco (http://www.rogerwilco.com) is a voice activated net radio system designed specifically to augment games. It is free, and there is a freely available SDK for using it within your own game. I run it in standalone mode, where it has nothing to do with the game itself, it just sits there as another application.

The interesting thing about Roger Wilco is that it doesn't screw up your computer. I run it over Unreal Tournament and it takes very little bandwidth (I don't notice any induced lag) or processor power (again, not noticable on my PII). The game sound comes through clearly and is not interfered with by Roger Wilco. The quality is almost as good as normal telephone. Previously I was not aware that this level of quality was possible.

The company is very intent on becoming the dominant net-voice technology. I don't know if they will succeed, but this is very good for consumers. They give away their software to get a large user base, and I suspect that if enough linux users wrote to them they would open the source for us to port or write a port themselves.

magic

Re:Roger Wilco

[Hast]

Since Microsoft are incorporating Battle communicator into DX8 I'd figure that RW's days are numbered.

There are several programs like this for Windows. None I've seen are crossplatform.

The ones I've seen that are crossplatform have had terrible GUI's. So terrible that I had to spend more than an hour to make it work. Not good. :-(

If a project like OpenH323 is completed then we can get down to business. IMHO protocols should never be proprietary, in the end it will make the users suffer.

would be better with a william_gibson'esque theme

[sanemind]

BTW, The telepath bit is a silly and detracts from the humor of the story.

It would be better with some sort of neuromancer-ish cyberpunk direct brain-machine connection sort of thing.

I'm impressed, kid... Write that up as a short

[GreyFauk]

story and submit it to a sci-fi publication...
That's really cute.
Excellent imagination... flows well... re-write it
a bit (I'm sure you know what I mean) and it's
a killer short story.. :)
Thanx...

Re:VON

[war2k1]

If you want to call someone, then pay for it.

I'm going to assume for a moment that this was a troll, and I'm also going to assume that they unknowingly (or knowingly, it's not important) brought up a very important point for discussion (although not completely on topic).

Why should you have to pay someone when you make a telephone call? You don't pay for email, except in a very obtuse way. What I think this issue is whether or not access to PUBLIC networks should be free or not. IMHO, there is no excuse for charging for any kind of network. Public network infrastructure, power, phone, net, everything should be nationalized. End of story. Right now, we might pay a few dollars for a universal access surcharce, but that's not what it's about. The phone company expects you to believe that it costs them on a per minute basis to keep up their networks. It doesn't. MCI/Worldcom's cost is about US$0.02 per minute, and you know what, most of that goes to pay telemarketers. There is absolutely no reason why we all can't pay, say, a $70 annual telecommunications tax, and have unlimited connectivity.

It is of course easy to argue that that's where it's going anyway and why bother with all that nasty government stuff. Well, that's what we have government for. The government should be progressive as well as protective. I mean hell if we pay all this money in taxes, shouldn't the government do something insofar as looking towards the future is concerned?

People around here seem to have a problem with monopolies. I don't. Just so long as they're not unregulated, controlling, tyranical monopolies. If MS had always had an open source approach, can you imagine how much better of a product it would be? No more waiting 3 years for a bugfix, etc. But the thing is a monopoly, properly used can be a good thing. In monopolies, you don't have non-compatible equipment to deal with or any of that. And if that monopoly answers to the GAO or some organization, then you wouldn't have things going on like AT&T charging US$0.35/min when it was completely unnescessary.

If we had a national telecom monopoly with progressive leadership, I think that universal access in this country with a reasonable fee is not an unreasonable thing to consider. DSL a couple dozen IPv6 addresses to every home!

And here, the argument that if we take away monetary rewards, we take away incentive for development just doesn't work. It's not like this service would be giving away free OC-192s to Digex or anything. Anyone who wanted to get more than their 'fair share' will have to pay for it. There will still be a market for high band products and services becuase the public network will need it, and there will always be private networks. On the consumer side, this national monopoly would have to fund R&D to be constantly improving the quality of service.

Of course there is the question of practicality and likelyhood. Is it practical? yes. Is it a good idea? yes. Will it ever happen? no.

Here's why not. All the phone companies are not interested in going out of business anytime soon. Bernie Ebers (head of worldcom) does not want to give up his billions in stock to accept a slightly smaller salary to better life in this country. Theres one reason all these guys are in it, money.

There are so many people who would hate it, not because it would threaten their livelyhood, but because it might reduce the value of their stock, if we had a free, high-speed, IPv6 network with say ten billion ip addresses reserved for phones worldwide.

But wouldn't you love it? If you could dial a 10 digit number into your IP-Phone (TM) and be connected to anyone, anywhere in the world?

It's pie in the sky i know, but isn't it fun to dream?

Re:Dialpad, ipmasq'ing

[paix]

i tried ipmasq'ing dialpad via their faq's howtos. i suppose my setup of masq'ing out of vmware/win98 might not fit exactly, perhaps that is why the howto was incomplete or not valid enough. anyhow, fwiw, i was told i need portforwarding perhaps that xinet would do, that is where i dropped out and bought a 2nd HD to run win98 and back up my primary linux HD anyway. anything besides dialpad bridge internet/regular phone lines? net2phone? anything else? cheers

Surfing the net takes far more bandwidth

[Russ Nelson]

Surfing the net takes far more bandwidth than a 2.4Kbps real-time bidirectional audio link. If you're that short on bandwidth, STOP READING THE COMMENTS!
-russ

Re:Dialpad, ipmasq'ing

[tsikora]

Use:
#!/bin/sh
#
# /etc/rc.d/rc.dialpad - Start portfw for dialpad phone
# access on Linux Servers with IP-Masquerading/Firewall.
#
# Add the following to /etc/rc.d/rc.local under
# Slackware or /etc/rc.d/boot.local for SuSE.
# ------------------------------------------------
#
# Start dialpad portfw:
# if [ -x /etc/rc.d/rc.dialpad ]; then
# . /etc/rc.d/rc.dialpad
# fi
#
# ------------------------------------------------
# Change x to your servers ip address.
# Change y to the clients ip address.
#

/usr/sbin/ipmasqadm portfw -f
/usr/sbin/ipmasqadm portfw -a -P tcp -L 24.x.xxx.xxx 51210 -R 192.168.0.x 51210
/usr/sbin/ipmasqadm portfw -a -P udp -L 24.x.xxx.xxx 51201 -R 192.168.0.x 51201
/usr/sbin/ipmasqadm portfw -a -P udp -L 24.x.xxx.xxx 51200 -R 192.168.0.x 51200
/usr/sbin/ipmasqadm portfw -ln

# SpeakFreely

/usr/sbin/ipmasqadm portfw -f
/usr/sbin/ipmasqadm portfw -a -P tcp -L 24.x.xxx.xxx 2074 -R 192.168.0.x 2074
/usr/sbin/ipmasqadm portfw -a -P udp -L 24.x.xxx.xxx 2074 -R 192.168.0.x 2074
/usr/sbin/ipmasqadm portfw -a -P tcp -L 24.x.xxx.xxx 2075 -R 192.168.0.x 2075
/usr/sbin/ipmasqadm portfw -a -P udp -L 24.x.xxx.xxx 2075 -R 192.168.0.x 2075
/usr/sbin/ipmasqadm portfw -ln

#

Try the MBONE programs

[randolph]

A little known and excellent set of free multimedia and confrerencing tools have been quietly developed for the MBONE. They are intended, naturally, for use in multi-cast environments, but most will work in point-to-point environments as well. Take a look at the University College of London Networked Multimedia Research Group web pages for details and a software archive.

Re:Anyone know of a good sound recorder for Linux?

[Dwonis]

Try setting your mixer. It's amazing how many boxes either have the mic turned off, or set really low by default.
--------
"I already have all the latest software."

Asterisk PBX and gnophone

[Ben Rigas]

I have seen these in action and its pretty cool, check out Asterisk and open source PBX system. Also see Gnophone by the same author.

Neat stuff.

Re:VoIP?! Give me a break!

[brockn]

Actually I worked for an ISP that provided free tech support to all customers.. Not one of them in our area code.. We used VoIP technology to save thousands a month on phone bills and yes it is not the greatest quality but sure good enough to win my support.. Even more so for being such a new technology.. It has a way to go before being implemented into the mainstream market but IS the voice of the future..

Multiple protocols = bad.

[smurfi]

How about interconnectability between SIP and H.323?

Open H.323

[smutt]

Have you tried openh323.org??

They have a standards based simple phone program
called openphone.

PGP

[OctaneZ]

While not currently available for linux (at least that I have been able to find) PGP puts out a great product called PGPfone. Not only does it do voice over IP in decent quality it also Encrypts your conversation at whatever keylength that you specify, without noticeable signal degredation.

Windows only tho

[cronio]

unfortunately, dialpad is windows-only. (Or was when i last checked a couple months ago).


One Microsoft Way

I've used SpeakFreely (v7.1)...

[quist]

...and the nice feature is that it is available for both *nix (Sun, HPUX, Linux etal) and Win Systems. So if you have family/friends on that commercial OS there is a IPvoice solution. The Win setup is unremarkable; download, turn the Wizzer loose and cross your fingers. On the *nix end, a bit of the ussual sound setup twiddling is required to get things going; however, nothing out of the ordinary.

The best part is the availablity of *nix CLI operation! You aren't forced into X to use it; handy on older laptops & PC's.

Dialpad

[tsikora]

Dialpad is an excellent web-based solution that works as a browser plugin. It's totally free. You can dial any telephone in the US free or anyone in the rest of the world can call a US resident. Unfortunately they do not support Unix. They however in their FAQ they have included instructions on how to make it work on Unix based firewalls/masquerading. Several people I know now use it instead of a telephone. I did for a while but just can't stand having a Windows machine on my home network. It also works ip to ip anywhere.

Re:dialpad

[Penrif]

Not only is Dialpad Windows only, it can only call computer-phone (its main advantage) in the US only.

Re:dialpad

[JoostFaassen]

This is the same thing but lets you call most of Europe too... Still windows only.

Speak Freely

[Parity]

I've used speak freely and been very happy with it. I only used the command line client, wrote myself a little script 'sfanswer' to respond to incoming connections, installed ALSA so that I could have full-duplex communication (speak and listen at the same time) and generally had a great geeky time with it. Sound was quite decent, better than PCS phones, actually, even on a 33.6 modem, though network traffic makes that a little inconsistent.

Meanwhile, my non-geek friend at the other end installed the precompiled Windows95 binary, played with menus and generally did the dumb-end-user thing and got it running with no problems...

So, for decent sound quality, interoperability with the non-geek world, pretty good reliability, a variety of compression options, - oh, and an echo-server to test your setup against - speak freely is pretty good.

Since I was happy with speak freely, I can't say how it compares to the others.

--Parity

Re:Dialpad, ipmasq'ing

[tsikora]

If you have problems with the other script try this:
#!/bin/sh
#
# /etc/rc.d/rc.dialpad - Start portfw for dialpad phone
# access on Linux Servers with IP-Masquerading/Firewall.
#
# Add the following to /etc/rc.d/rc.local under
# Slackware or /etc/rc.d/boot.local for SuSE.
# ------------------------------------------------
#
# Start dialpad portfw:
# if [ -x /etc/rc.d/rc.dialpad ]; then
# . /etc/rc.d/rc.dialpad
# fi
#
# ------------------------------------------------
# Change x to your servers ip address.
# Change y to the clients ip address.
#
# Dialpad

/usr/sbin/ipmasqadm autofw -A -v -u -r udp 51200 51201 -c tcp 7175
/usr/sbin/ipmasqadm autofw -A -v -u -r tcp 51210 51210 -c tcp 7175

# SpeakFreely

/usr/sbin/ipmasqadm portfw -f
/usr/sbin/ipmasqadm portfw -a -P tcp -L 24.x.xxx.xxx 2074 -R 192.168.0.x 2074
/usr/sbin/ipmasqadm portfw -a -P udp -L 24.x.xxx.xxx 2074 -R 192.168.0.x 2074
/usr/sbin/ipmasqadm portfw -a -P tcp -L 24.x.xxx.xxx 2075 -R 192.168.0.x 2075
/usr/sbin/ipmasqadm portfw -a -P udp -L 24.x.xxx.xxx 2075 -R 192.168.0.x 2075
/usr/sbin/ipmasqadm portfw -ln

#

Re:VON

[aenea]

No. I would not love it. I'm not sure what is scarier: a government-run internet or that you think it's a good idea.

You can seriously sit there and think that a government run monopoly will bring innovation and efficiency to the internet? That it will be nimble and willing to provide cutting edge technology to the country? That it will provide free and unrestricted access to everyone? How long do you think Napster would last on a government internet? Hell, here's an on-topic question: how long do you think IP phones would last on a government internet before some bureaucrat decided they were a waste of precious communal bandwidth?

I realize your premise is based on magically staffing this monopoly with enlightened, caring, technically savvy bureaucrats, but honestly, really, you believe that will happen? You believe that it will stay that way after five years? After ten?

It's amazing the number of people that believe that centralized control is good. Or that sending your money into the government somehow means that it will be spent in a more efficient manner.

I would love to have a high speed Ipv6 network. I love IP phones, but you can't get it for free. Someone, somewhere, has to pay for it. Why is it so unreasonable to expect people to make money while providing you with that service?

kphone (aka KT&T)

[vektor_sigma]

I'm the author of kphone, a VoIP application for KDE 2.0 which uses the SIP signalling protocol for call setup.

SIP is the IETF standard for signalling of VoIP calls (as well as other multimedia conferences). It is supported in products by 3Com, Nortel, Cisco, ... Very cool.

You can check it out in the kdenonbeta package of KDE 2.0.

Re:VON

[war2k1]

I have no problem with paying for access, wht i do have a problem with is buying Bernie Ebers a 52-foot yacht and 35 cars. There's a lot of waste and I think that properly administered, it could be a good thing.

Re:Use the phone?

[Anonymous Coward]

Don't you realize that by posting on slashdot you're using up bandwidth that the rest of us could use? Get off the web and go back to gopher!

VoIP? Isn't it really Audio/Video over IP?

[strredwolf]

Serious though on this. All we're doing is digitizing audio (and possibly video) over an IP link and keeping it under 2.4K/sec. There's alot of algorithms that are out there and can do it (performance not mentioned but still important).

Dr. Dobbs Jornal had one called idtAudio, and did an audio stream. The decoder was in Java, and the encoder in C. It streamed over HTTP. You can get the source there.

DDJ has covered alot of the compression field, and has many articles on the topic.

---
Another non-functioning site was "uncertainty.microsoft.com." The purpose of that site was not known. -- MSNBC 10-26-1999 on MS crack

Re:VON

[DrEldarion]

Thank you for your opinion, Mr. AT&T Executive.

-- Dr. Eldarion --
It's not what it is, it's something else.

Other open source sites for VoIP

[cullenfluffyjennings]

Also check out www.vovida.com (I work there) who have put out several open source stacks for VoIP and a software phone that uses SIP and runs on Linux with a Quicknet phonejack card. Vovida has also sponsored a project to create an open source client like you want. It is at http://sourceforge.net/project/?group_id=5560 and the RFP is at http://www.sourcexchange.com/ProjectDetail?project ID=20