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Nexland Pro800Turbo Load Balancing Router Review
An anonymous submitter writes "Found this review today over at OverclockersClub.com. Apparently this router can load balance two broadband connections like DSL, Cable, or T1. The router can also act as a backup feature in case one of the broadband connections goes down, the router will automatically switch to the connection still working." At $400, it's not gruesomely expensive either, and I guess if you're willing to pay for two broadband connections anyway... The spec sheet (PDF) has more information.
Why not a software solution, instead of dropping 400 bucks? Ultra Monkey is a package including LVS, prepared mostly by Horms.
Super Sparrow is a distributed load balancing package also by Horms (formerly of VA Research|Linux|Software|Spacecraft|Doohickeys) that uses BGP route information to decide which server ought to service a request. Neat stuff. Super Sparrow is not ready for deployment, and appears to be on a back burner (due to VA's disinterest in such things these days, probably).
LVS is the project to beat in this space, by a long ways. It is very very solid, and extremely efficient. Wensong is quite an impressive nerd.
The theory of relativity doesn't work right in Arkansas.
I just can't stop laughing.
You can use NAT to hide the real servers from the Internet if you like. This allows you to use most any web server you like (such as IIS), but more fancy routing tricks can be done with Unix or Linux servers for even better results. We use NAT at our site (university EE department) and it can handle more load than we will ever receive -- our objective is high-availability. Also, you can use different methods for different server clusters on the same director (e.g. tunneling tricks for Linux apache servers, and less magic for IIS).
And LVS can be set up such that once a user connects to a particular server, his subsequent connections go back to the same server.
Useful links:
The theory of relativity doesn't work right in Arkansas.
First, this router has been out for a long while.
Second, 2 WAN connection AND modem/ISDN backup is sweet for an out of the box solution. Not a bad price, as already stated.
However, and third, a regular PC with a DFE-570tx or it's successor, the 580tx, by Dlink, allows 4 10/100 ports per pci slot. And regular 10/100 nics can be found for less than $10 shipped. You could build a machine for about half the price with greater future expandability.
"If the Duplex LED is flashing this means their has been a collision on your network. This happens when packets are dropped for some reason or the packets have been misdirected. This usually only happens when two computers are using the same IP address and this usually only happens when you specify an IP address rather than using the DHCP feature built in the router."
Network collisions occur when two hosts try to submit simultaneously. The NIC listens for the resulting static on the network line (as static is produced when the signals garble), waits a random length of time, and retransmits. This happens (I believe) at a lower-than-protocol level.
From the article: Features: "For Businesses with Heavy Traffic Loads"
Seriously, if you are a business and have a heavy traffic load or really need a good connection, you don't use broadband... That's good if you have a medium traffic load or need a somewhat reliable connection. I would never trust a broadband connection to be fully reliable, unless it's a dedicated pipe.
And I guess that router is only for normal surfing, no servers. If it constantly switches between two connections, the IP must switch too, right?! I guess one could have a DNS set up with the two IPs but if one of the connections go down, the dns lookup will find the invalid IP every now and then, making the web-site or whatever being run a bit unstable. So this is not a solution if you want to run a service behind it, only several clients using a lot of bandwidth that needs to be load-balanced.
This is not a load balancer for server farms.
This is for, say, having 2 internet connections and using them both. Getting cable & dsl at home and making use of both of them.
I'd been wondering about load balancing a pair of ADSL lines. This confirms my hunch.
In the UK at least, the basic home service is 512k down, 256k up and a single IP address. The cost of 1mb down 256k up is much more than twice the basic cost, presumably because it is counted as a business service. Getting 2Mb down 512k up is a lot more again. It would be far cheaper to get 4 lines converted to ADSL with the added bonus of some redundancy.
As far as I know the pricing is set for market segmentation rather than for any inherent extra costs for the fatter pipe. The same home user is unlikely to hog the extra bandwidth, they will just get a better service.
Anyone know any real objections to this from the telcos perspective?
As for failover, that would be really easy to do regardless of the load balancing support. You just need a cronjob that checks if one of the connections is still up, and reconfigures routing & firewall on timeout.
___
If you think big enough, you'll never have to do it.
After two long and useless pages that guide us through the setup screens on the router, we get a test of half-life pings, and downloading from two websites. To add insult to injury, the reviewer uses IE, which is known to report little more than crude approximations of transfer rates.
The half-life pings aren't telling us anything, as it's a well-known fact that pings jump when your connection is saturated. It doesn't matter if you're multiplexing two of them.
Win2k/XP can both report raw ethernet throughput using perfmon. This would have been a much more useful and reliable benchmark.
Too many issues are left unaddressed: does this solution double your upload or download rate to a single host? Are you accessible through a single IP, and if so, which one of your broadband connections is used for this?
Can anyone who's actually used this provide some insight?
Nix absolutably seriousness.
I have been unsatisfied with the Pro800Turbo. It is not able to properly act as a DNS relay when working with multiple WANs (ISPs); if one of the ISPs goes down, the unit sometimes fails (so much for the backup capabilities); and the unit just hangs every now and then.
I have complained to Nexland technical support numerous times about the DNS problem. I purchased the router several months ago, and all they've come up with so far is the obligatory "try the new firmware" (which didn't solve the problem).
I would not recommend purchasing the Pro800Turbo at this time, as the hardware/firmware is just not good enough yet (and the tech support is not able to compensate for this shortcoming).
I am now on a multiplexing BSD implmentation (OpenBSD), the two feeds are load balanced pretty nicely (and using just an old P5 box). I don't believe I'd ever go back to the NexLand box again. Also, Linux people might be interested in load balancing in their kernels, I've not tried it msyelf, if someone has please let me know if it's worth looking into.
My Netopia SDSL Router does the same thing. Of course its SDSL Only, plus its technically a business class router, its about the same price, but I got it free with the business SDSL I signed up with uunet. It has two SDSL ports on the back, by default you can only use the second one as a backup, which switches on only when the primary fails. However a 20 dollar firmware upgrade lets me bond them. So for example, if I had two 384k bonded connections, I'd have one 768k connection. Too bad its too expense to make it worth my while =)
..There's a-dooin's a-transpirin'
Software solution? Are you kidding? I don't know of any software that runs without a computer underneath it, and it's damned difficult to put together a reliable machine with a case and four network adapters for less than $400.
Software isn't free. It requires hardware. When you get dedicated hardware and software that can be configured by someone who doesn't frequent slashdot, you've got a compelling solution.
Anyway, I installed this box at a client site four months ago (two Covad DSL lines), and it's been flawless the entire time. I highly recommend it for situations where better bandwidth isn't available. It's about as easy to configure as a Sonicwall, not quite as easy as a Linksys. Web managed with a gotcha or two in the UI.
aka Matthew at SlashNOT/!
Can someone explain how this works to me?
As far as I know, to even do that with big connections you need to go through the same ISP and PPP bond them together. Say I have two T1 lines, one from Sprint and one from UUNet. Each one can transfer 1.54 megabits per second, theoretically. Even though I have two T1 lines, if I go and connect to some remote FTP server, it's only going to send data back to Sprint or UUNet. It can't figure out "hey this guy's got two connections, I should start sending him data on both of them" and suddenly be able to download twice as fast, can I? I may have two T1 lines, but I still can't transfer a file faster than 1.54mb/s.
If if you have two T1 lines from the same ISP (say I have two from Sprint), it takes special configuration, putting them together with a PPP bond, to make them work as one pipe. As far as I know.
Now apply this logic to the type of connections you might have in your apartment. Say you have one DSL connection and one cable connection. Are they really going to increase your transfer speed?
I can see how you'd be able to SEND data faster, but how does receiving work? Can someone explain this to me?
One of the many things I hate. thingsihate.org
So how about the bandwidth doubling idea? Great, but wouldn't it be better if the ISPs just changed their business model on cable modems? They already have with DSL. With DSL you could just upgrade to a higher level of service (more bandwidth) instead of consolidating two lower bandwidth lines? With Cable modems, the situation is even simpler. At the modem level, the bandwidth is almost always throttled back. Doesn't it seem idiotic to consolidate two bandwidth throttled lines instead of just opening things up a little? How bout 3Mbps instead of 1.5 (for most AT&T subscribers).
It just seems inane to come up with a hardware or software solution for something that's really a business model issue.
A beginners' guide to Portland, OR?
PhysicsGenius is a well-known troll.
That review really enforces the stereotype that all overclockers are uneducated 34 year old A+ graduates with GED in hand who spend all of their pathetic life playing Quake and Half Life. Flame me or mod me down if you must, but I'm tired of reading 2nd rate reviews -- that's why I read Slashdot, not overclockerswhatever.com.
All through the several pages there are dozens of spelling, grammar, and simply sentences that just don't make sense. That's not to say that I don't mind that, but in this case the content was the same -- a bunch of screen shots with related commentary of someone who on a good day can setup a Linksys router with no issues. I especially like his "(router talk)" parentheses explanation as if to explain the mystic Mbit unit of measure to us simpletons.
Please, leave the detailed screen shots for the manual and the self-serving explanations to someone with can do more than double click on his Dell. We want to see why we should buy this thing in the first place and how it performs, not how to configure it.
As I skimmed over the first several pages looking for graphs I was instead greeted with some very scientific tests of ping time from within a multiplayer game. Then the guy goes on to download two random files from a random location on the Internet as a testament toward the performance of the router, using a web browser.
No technical or scientific consideration was found in this review, and I found it insulting to read. If you must review something, at least know a little about what you're reviewing, and especially how to test it. Don't waste your time reading that nonsense. In fact, I am surprised it was posted to slashdot considering the quality and the background of the reviewer.
This guy should go back to reviewing the newest shoot 'em up or writing up the procedures for overclocking his celeron, and stay away from stuff that is ever so slightly more complicated involving more sophisticated testing and technical reporting.
"I'll just chip in a bit for RedHat: I actually have that installed on my university machine." - Linus, '95
Make sure your ISP isn't putting your traffic through a cacheing server, or this won't work.
The Virtual Bookcase: book reviews
Until I went to their technical support forum and saw that in some cases, the router would simply lock-up. I accept lock-ups on computer software with great difficulty, I won't tolerate it in firmware/appliances. I went for a sonicwall SOHO-3 instead, the downside is that everything is more expensive with the sonicwall, but the upside is that every add-on you get, you get your money for it (exept the content filtering which utterly sucks).
--- Metamoderating abusive downgraders since my 300th post.
Correct me if I am wrong, but I'm pretty sure there are quite a few people on slashdot that are confused as to what this device actually does. It is a load balancer for the connections. What this doesn't mean, you hook a DSL line and a cable line to it and get the sum of the two speeds. What it does mean, is that for outgoing connections, you have seamless integration of two lines for redundancy purposes.
For example: once the two lines are plugged in, when you are surfing around and hit a website, the router automagically picks which connection (DSL/cable) the request goes out on. If one of the connections happen to be down, it picks the one which is not (thus the load balancer part).
One interesting thing to note though. It may actually seem like the sum of the two connections from an application standpoint. Examples being web browsing and ftp'ing.
In web browsing, I know that in IE and Mozilla, you can select the number of outgoing connections that the browser will use in fulfilling a web request. So you could end up getting the http reponse (text-only) from one connection and using the other (seperate outgoing web request) to retrieve the images on that page. In most cases, you would likely speed up graphics heavy pages quite a bit.
In ftp'ing, some of the clients (along with the download managers) allow you to use multiple tcp streams to receive your downloading file. The software has a file to receive which it starts multiple receives going. In theory, you could run say, 1 tcp stream per connection, and be receiving the same file over the two connections independently, but achieving an overall rate equal to the sum of the two speeds.
The whole thing kinda reminds me of the pigeon-hole principle in a wierd sorta way.
But anyway, I imagine a linux/BSD solution to be cheaper (given low-end hardware requirements).
E
First, about the review: no stress, stability or soak testing. Didn't test WAN connections from different providers. Didn't even try different packet sizes during pings. Routers have industry-standard tests to run them through, and going through the HTML pages and transferring a file does not constitute a router test/review.
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Warning: we have heavily tested the Nexland Pro800T. The Nexland Pro800 Turbo +hard+ crashes daily and looses packets. Once a week it looses all its config. We have had the box replaced multiple times - no help. We have tried their old and newest firmware. No help. It is getting so bad, that Nexland actually shut down their user forums (see www.nexland.com) because so many people are complaining!
I +do+ not recommend the Pro800 Turbo router. The only way we can keep the thing up is to have an automatic ping/tcp/http tester that power cycles the darn thing when it crashes multiple time per day.
Anyone else experiencing these issues?
There is another option. Compex has redundant + load balancing router (NP15-BR). See:
http://www.cpx.com/proddetail_b.asp?c=Broa...%2
Anyone use this?
Hope this helps,
Marc