ADSL load balance question

[f2b]

Hi

Load balancing using a 2800 with 4 x wic ADSL cards.
How does the load balance work? For example if we have 4 x 7MB ADSLs (7Mb downstream, 700Kb upstream). Would this then mean around 28Mb downstream and around 3Mb upstream?

I cannot imagine how the packets would get to their correct destinations upstream. I can understand downstream the Cisco would do the packet reassembly.

Thanks

 

[burtsbees]

Instead of load balance, perhaps you mean bundle them, like all in one 28MBps pipe? That is a MLPPP config, or multi link point to point protocol. Is this what you mean? The way they are now, I cannot be sure which line takes priority over which...

Burt

 

[f2b]

Yes, that is what I ment. Making use of all 4 ADSL's. I heard somewhere that it will only work in one direction and I think it is downstream. So uploading will still be at around 700kbps? How would the other end know what to do with the packets. For example, if the ADSL's are on different switches/routers at the ISP end, how would the packets get re-assembeled?

Thanka
A

 

[ADB100]

Bundle? You would need some sort of agreement between you and your ISP? Multilink PPP etc.........

I assume you actually mean load-balance? If that's the case then it's all down to your configuration, and no you won't ever achieve 28Mbps......

You might get 7Mbps per session but that's about it....

I might be wrong but you need to explain a bit more about the ISP service and what you want to achieve....

Andy

 

[voltron1011]

I'm a bit curious as to how you'd do this as well (esp with ADSL)...

 

[f2b]

Ok, lets call is load balancing as that is really what I am after at the end of the day. Ie, making user of 4 x 7Mb ADSL's.

If load balancing only gives you 7Mb out of a total of 4 x 7Mb ADSL's then why are Cisco providing this. I mean what's the point?

We are based in Spain with Telefonica so forget about agreements. They would rather have a few weeks to maybe think about about it first :O) How can this work to it's potential. Am I wasting my time?

 

[ADB100]

You have to understand the traffic flows here. If you have a single host internally then for a single application (for example an FTP download) the maximum you will achieve is 7Mbps. If you have two host's internally then as long as the router sends one converstation down one ADSL line and the other down another, then potentially each host may achieve 7Mbps. Depending on the load balancing algorithm different applications (or sessions) on each host may each achieve 7Mbps.

Apply that logic to having many hosts internally and then understand how the traffic flows will happen - the router will send different flows down different ADSL links but it must maintain state for each flow so it won't split the same session over multiple links (this is what Multilink-PPP does, but this requires both ends of the link to agree that all links are part of the same logical connection).

HTH

Andy

 

[plshlpme]

how andy explained it is spot on..

in the other case if you were able to put them all into a multilink bundle you would have the 28mb at your fingertips all the time...
I dont think many isps support this though..

so really cisco is telling you what it can do.. you just need to convince your isp to do it.

it will be possible for you to utilize the whole 28mb as is.. but as stated above it wont be available all in one shot.

 

[f2b]

A little late I know, but thanks guys for your input. Much appreciated.

Thanks
A