load-balancing t1s

I have two point-to-point t1 lines, with a 1720 and a 2621 on the ends. I was under the impression that by simply having routes of equal costs going through both t1s, that packets would be spread among them, at least to some extent.

However, in practice it doesn't work that well. Any one host only seems to be able to use a max of about 1.5mbits, and even with multiple connections from various hosts, I never get to more than about 2.0 or 2.3 mbits total throughput. Looking around, I see that nearly all references to load-balancing t1s as using CIF, and our feature set (or IOS version) doesn't appear to support the commands that they utilize.

So... do I need a certain feature set in order to make this work, or will I need to look at upgrading the IOS version, along with accompanying flash and memory?


Reply to
Steve Wolfe
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In order to run per-packet load-sharing,

1720 will need either to support CEF or have fast-switching disabled.

So, try disabling fast-swiching, like:

interface Serial0 no ip route-cache ip load-share per-packet

Regards, Everton

Reply to

I prefer to use Multilink PPP in this scenario.

Reply to

Agreed. I tried both solutions and had better results with mppp in regards to voip jitter and etc.

Reply to

Just a minor note ...

per-destination is the Cisco recommended method for voice using IP CEF load balancing. Per-destination always uses the same path. Per-packet could result in out of order packets.

If you want to check for yourself, look for the Cisco document 'Troubleshooting Load Balancing Over Parallel Links Using Cisco Express Forwarding'

Reply to
Ken Johnson

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