Solved: load balancing to get more throughput over WAN links

carl_townshend · ‎08-29-2018

Hi All

I have a question,

Is it possible to load balance a single host to host tcp session between 2 WAN links?

would this be per packet load balancing?

I tried to enable it on my ASR routers but it would not let me, why is this?

also I hear that it is not adviseable to do this due to packets arriving out of order etc?

has anyone any good experience of this and working well?

cheers

Joseph W. Doherty · ‎08-29-2018

For a single TCP session? Yes, per-packet load balancing would be one way to split that flow across two WAN links. (NB: MLPPP might be another.)

If the ASR doesn't allow it, it might be because it is generally is not advisable to use it, for the principle reason you note, i.e. out-of-order packet delivery. (NB: MLPPP doesn't have this issue.)

I've used it, on very low bandwidth WAN links, also they were not ASRs. Had great load balancing, unsure whether it was good for applications.

In theory, if some very special cases, it might be okay/good to use, especially if you can configure hosts' TCP parameters, but in general, again, best to avoid.

View solution in original post

Joseph W. Doherty · ‎08-29-2018

For a single TCP session? Yes, per-packet load balancing would be one way to split that flow across two WAN links. (NB: MLPPP might be another.)

If the ASR doesn't allow it, it might be because it is generally is not advisable to use it, for the principle reason you note, i.e. out-of-order packet delivery. (NB: MLPPP doesn't have this issue.)

I've used it, on very low bandwidth WAN links, also they were not ASRs. Had great load balancing, unsure whether it was good for applications.

In theory, if some very special cases, it might be okay/good to use, especially if you can configure hosts' TCP parameters, but in general, again, best to avoid.