We have a cable connection that occasionally goes down. To avoid problems delivering projects to clients, it’s worth it to us to have a DSL line brought in as backup (it’s only about $400 per year).
Once we have the two Internet connections coming in, is there any way to take advantage of the combined outgoing/incoming bandwidth?
If they have to remain separate, how do we monitor the secondary (slower) line for connectivity? Can 2 computers that are connected to the Internet via different pipelines be part of the same internal network?
I have enough spare parts to put together a machine with either Windows 7 or Linux on it if necessary. The only additional criterion I can think of is that whatever solution should maintain the Gigabit intranet connection.
Get yourself a “load balancing router”. It’ll cost you about $200 but it’s made for exactly this sort of thing. It will load balance when both connections are running, and will make sure that all of the traffic goes to the one that is working when one fails.
I hear that some of them can be a bit of a pain to set up and configure properly, but I haven’t had to do it myself.
By load balancing, does it take advantage of the size of both pipelines or just make sure one is there in case one maxes out?
The main idea is for the upload speed (our download speed is fast enough to never really notice slowdowns). If we’re uploading a large file, will load balancing max out (assuming nothing else is going on) the speeds of both connections, shortening the overall time?
You have to watch the specs on some of these, but if it is truly a load balancing router then it will try to balance out the packets between the networks. If you are uploading or downloading a large file it will split the packets over the two links, decreasing the overall file transfer time.
I don’t have any direct experience with broadband load balancing devices, but do have some knowledge of how internet traffic works.
When uploading a large file over a device that has two different connections (with different carriers) you are going to be limited to your fastest upload speed in most cases. If you are uploading a file to a website you only have one session, and the load balancers can only use one connection per session. The load balancing method they use is to alternate between internet connections for different sessions, so if you were uploading two files simultaneously it would put one file on one connection and the second on the other. It works the same way for downloading.
For general web traffic you will see some difference in download speed, since most web pages are actually composed of pictures from multiple sites, so each page will have more sessions it can spread out between connections. Also, download programs like BitTorrent where you are downloading chunks of files from many different people will probably max out both connections.
There are methods of combining connections at a lower level that aren’t limited by the TCP session, but these require that both connections go to the same carrier and require more specialized configurations and equipment, so they aren’t very common for broadband connections.
Which specs to watch? How would you phrase a question to pre-sales to avoid this? It would be the exact opposite of what we’re looking for. Don’t mind overhead, reducing the theoretical speed of straight addition of the two speeds to something between each individually and their sum.
They’re a cruel company. The 10/100 home office routers are a few hundred bucks. The first one with Gigabit capabilities jumps to about $500 (Gigabit is helpful here as we share files between each other in the tens of gigabyte range).
I think this is what you want – for downloads to be split between the two connections and simultaneously piped through both. The opposite is what you don’t want, where the 2nd connection is used only when the first is down.
Have you considered putting a gigabit router behind the load balancing one that faces the Internet? You don’t need gigabit speeds to the Internet, just in your LAN.
Also, I’m not sure if this will help with uploads unless you write a special program to split your uploads across the two connections. I’m not saying it’s impossible; I just don’t know whether consumer load balancing solutions are smart enough to do this.
They do it with HTTP downloads, but uploading is different because you’d have to establish two separate FTP sessions, your upload app has to know to split your uploads into chunks, and the receiving system has to know to recombine them.
That, or at least the sending program has to split it by file so that half the files will be sent through the second connection – but that still requires two FTP sessions, and if you’re using SFTP, encryption and authentication further complicate matters…
Hmm, an interesting solution might be to set up a custom BitTorrent-based transfer solution on both ends. That way you won’t even need load balancing hardware/software because BitTorrent (I believe) can seed and download through all available interfaces at both ends. It does this at the application level in a very intelligent way; not only will it split files across the available connections, it will chunk each individual file and send the tiny chunks across different connections. If you upload big files with minor changes, the chunking will in essence act as a delta patcher – meaning only the bits that’ve actually changed will get sent (and recombined into the rest of the file at the other end), saving you some bandwidth. It also checksums each chunk sent, ensuring file integrity.
