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Channelized DS3 with Linux?
minion asks: "We've been struggling to find a channelized DS3 card for Linux that is a standard PCI format (not CompactPCI, mPCI, etc). I find it hard to believe others out there don't want the same, as a lot of ISPs could save a lot of money this way, since Cisco routers that handle channelized DS3 *start* at $30,000! I've found this card, but that is all that I've found. It would be great to dump our current Cisco, and use it as a spare if our Linux router fails. Does anyone else have some experience with this?"
Found this
And found this
If you are talking about the former - you might be suprised to find out you won't be much under 30K (those reliability things are expensive), if not - how much are you willing to give up in reliability (6 9s w/ Cisco - 3 9s with Linux + cheap hardware) and what is the cost of the downtime.
If you all ready have the Cisco kit (you did say you would run it for redundancy) - why change a working configuration for Linux ? Is it because "Linux is cool" or is there a business reason. If it is the former - I doubt you will be successful. If it is the later do the analisis above and see what the answer really is
I have mod points and I am not afraid to use them
Uh, I may be missing something but if you already have the Cisco gear to run your setup why on earth would you want to store it on the shelf and run a Linux PC in its place? Cisco devices are designed for exactly the application you want meaning they're fast and reliable. I haven't priced DS3 pipes in a while but if you're purchasing anything that even has DS3 as part of it's name I'd keep with the Cisco gear since there's obviously *some* decent cash floating around.
I dunno. But what I'm hearing is: "We've got a Formula One car that we'd like to keep in storage while we go to the Japanese Grand Prix in our NASCAR Monte Carlo, `cause the Monte Carlo is cheaper."
This is an interesting point. A DS3 is 54 Mbps, or thereabouts, and PCI runs on a 66MHz bus, right? Wouldn't you be wasting bandwidth if you put it into a PC? I thought that was why they are putting the 100Mbps ethernet onto the Northbridge to avoid the PCI bus entirely. I have to admit to only a vague understanding, so if anyone out there knows better please chime in.
I think <10kUSD can get a used 7200 series router and channelized DS-3 (PA-MC-T3) card on eBay, not that I am recommending that approach, but it is a common configuration.
Larry
Okay, I was able to purchase a good condition cisco 7206 with the npe-300, latest ios, with a dual atm ds3 interface for 12k, and an 8 port IMA t1 card, gotta love ebay. why bother with trying to make a high end and "reliable" linux router (i'm sorry, but linux doesn't have nearly an efficient enough network stack to handle channelized ds3 i/o, and isp's that make the step up to ds3, generally move to multiple ds3's, and I'm not doing that on a linux box!), with pci network cards, to replace a good ol' cisco router? and moving to sonet? blah! sonet ds3 cards on a linux box? you're kidding right?
I don't know about $30,000. I have a FlexWan, which is a PA card adapter for the 6500's [which is the pricey but elegant way to go], and a PA-T3 and on the 7206VXR. They can be had for much less than $30,000, especially on ebay, but you can get prices down on Cisco if you aren't dumb enough to pay MSRP. You can also get PA-T3+ and PA-2T3+ for your FlexWan or 7200.
Here is a 7206VXR for ~$8000 that has what you want.
I'm no great fan of IOS, I much prefer Junos and my Juniper M10, but you'd be psychotic to even pretend a PC [despite the fact that Olive/Junos is based on FreeBSD from the PC, but each PIC uses network processors] could handle a T3 the way a Cisco or Juniper could. Yeah, its not very much bandwidth, but there are a lot fo interesting things these real pices of equipment can do for you.
Also, using a monitor OS like IOS and network processors is a lot better than interrupt driven crazyness that goes on in a PC.
In fact, I have a spare spare PA-T3 card I would sell you.
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The thought of relying on a standard PC to drive/frame/time/switch a DS3 makes me nervous. There is a lot to be said for Application Specific Integrated Circuits(ASICs), which is what the Cisco uses.
Cisco's routers are expensive. Perhaps Nortel, Juniper, Foundry, Fore, Riverstone, etc might be less expensive but offer similar functionality and reliability.
How many channels are actually needed from the DS3? A Cisco 3600 can drive up to 12Mbps on a HSSI interface and would cost a lot less the $30,000 but, you couldn't go beyond 12 Mbps.
How much does a DS3 cost you? In my area, the monthly cost of such a circuit is such that a one time cost of $30,000 for hardware is really no big deal.
as my grand pappy said: Use the right tool for the right job... You could use juniper or nortel. But just do it right.
PCI Adapter
PCI Adapter
Linux Router Page
Question is, why would you want to? Most ISPs will 'lease' you a router when you get any type of dedicated internet connection. They also have this little thing called SRA or MTTR (Service Repair Agreement or Mean Time To Repair). If your router blows, they'll replace it in a matter of hours. If you own your own equipment, you'll either have to buy a spare (doubling your price) or suffer long downtime (How long of a downtime are you willing to afford?). ISPs also buy routers in bulk. So what may cost you 30,000$ for a Cisco router, ISPs pay a fraction of that. (And I dunno where you got that it starts at 30,000$.. there are much cheaper routers that will do channelized DS3, including in the Cisco family). You also have to think... going the Linux route... what happens if the motherboard blows, or the power supply, or the harddrive, or the NIC cards? You'd prety much eed a complete 2nd system as a backup. What about vulnerabilities? If this is out on the net, Cisco IOS is much more stable and secure than a linux box. How many man hours are you gonna spend patching stuff, compared to just leaving the Cisco router alone cuz it's not affected? If you do need to upgrade, upgrading IOSs is a joke. This isn't some dinky little home DSL connection where a Linux router is better than a 50$ Linksys router. You're trying to make yourself intelligent, but really, get a clue.
It's better to burn out than to fade away
33Mhz X 32 bit PCI = 1 Gigabit
66Mhz X 32 bit PCI = 2 Gigabit
66Mhz X 64 bit PCI = 4 Gigabit
Actual throughput for each of these bus types is a bit less than the theoretical values above. However, having multiple 54Mbps cards on a single 33Mhz PCI bus should not be a problem from a bandwidth perspective.
Maybe, maybe not...
I took a quick peek at those cards and they both looked like clear channel DS3. I'm kinda going along on fuzzy memory here, but I think that if its channelized you need a M13 framer on the board to break out the T1s. I don't think you'll be able to do that in software. Something like this card may do the trick, but its only appears to have WinNT and VxWare support. The problem with the clear channel cards is you have to break the DS3 down into DS1 channels and provide framing on those channels which is quite I think is generally done in hardware.
It's not as if Cisco has no competition and can charge whatever they want. The reason Cisco chassis and line cards are so expensive is because they are GOOD and FAST. For example, the Catalyst 6500 has a 32Gbps backplane and with a SFM, a 256Gbps Switch Fabric. Fast WAN connections are generally only used on networks with large LANs and such organizations can justify something like a 6513, which loaded with a few cards, clocks in around $125,000.
"Nature doesn't care how smart you are. You can still be wrong." - Richard Feynman
hmmm I run an ASI dvb card at DS3 rate on a 2g Pent mobo and pump out on the 100 BaseT. A DS3 to ASI convertor is about 2000 AUD. The ASI PCI card is 2500 AUD.
Processor load is 10%.
Regards.
Are you using a full DS3 at the moment? Are you using all the channels for data, or mixing voice and data?
Are you trying to tie in multiple remote sites? What other interfaces are you looking at?
I.E. a Chann DS3 coming in and fast ethernet on the inside? etc...
What about using an external MUX for the Ds1-Ds3?You say you have a cisco box, what model and why are you looking to replace it?
Without knowing more, I would say the Cisco 3600 is your best all around choice. Check Ebay. The main downside with using ebay is OS updates and/or patches.
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It may be too late to post, but this might still be good info for somebody:
Until last year, I ran an ISP. Even though we had a pair of 7206VXRs (and access to ebay), we didn't use Cisco CT3 cards. Those cards were too expensive and had these awkward limitations: Bonding T1s was a problem. Traffic shaping doesn't work well. And you can can't have multiple sub-T1 rate customers on a single T1 channel (for example, you can't ask the phone company to put 6 256Kbps (256Kbps = 4 DS0s) customers on a single T1). Our ISP used all three of these features extensively.
Instead of a Cisco or Linux card (we looked at both), for each CT3 circuit, we bought a Tasman 6300. Plus we kept a "cold spare" 6300 unit on site for an inexpensive kind of N+1 redundancy. A couple of years ago, each 6300 cost $10,000. When our internal routing became complicated enough, we starting running OSPF on everything, including the 6300s.
You still might use Linux routers as the core of your network - in my latest venture we use a pair of fast Linux routers running HSRP with a group of layer 2 switches. We bought Cisco layer 2 switches. I am not stuck on Cisco, but, to make this work properly, you need to be able to create multiple VLANs (so each subnet's traffic is separate) that can span physical units (when redundancy is required), but you also need to have ports that can be in multiple VLANs simultaneously (so you don't have to buy a zillion Ethernet ports for your Linux routers). Ciscos can do this and I got a good deal on used equipment with ebay. With this setup, the layer 2 switches provide the physical Ethernet connections and your Linux router(s) provide layer 3 (and higher) features - iptables, traffic shaping, whatever. If you buy all the same model Cisco layer 2 switches, you can keep a cold spare for inexpensive kind of N+1 redundancy.
For connecting non-channelized T3s to Internet backbones (or wherever), you can use Cisco 7200s, Linux routers with non-channelized T3 cards or even a Tasman 4100. If you plan to run BGP with multiple backbones, and you are not a super-duper BGP expert, then a used Cisco 7200 with adequate memory for full backbone BGP tables and a fast CPU is probably a good choice: It will work for sure, you can use sample configurations from your carriers and, chances are, you and the guy on the other end of the support phone line will be using the same equipment when things go wrong.
Now I know these setup aren't true N+1 redundancy, like you get with a phone switch or UPS. But even with a Juniper, if a line card fails, the customers served by that line card are dead until somebody physically swaps it out. If you have techs on site (or nearby), with a cold spare on site, you can recover from total switch or router failure pretty darn quickly.
You said that you were running HSRP on two Linux boxes.
HSRP is a Cisco proprietary protocol, and I know of no Linux implementation (I did a quick google for that, which confirmed what I'd already suspected).
Has someone implemented HSRP on Linux, or did you do this with VRRP (The open standard HSRP workalike, for which there is a Linux implementation), or did you use another means alltogether?
Again, just curious...
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Oops. You are right. I meant VRRP between Linux boxes.