[Link Bundling Restrictions on XR 3.4.1]

Unanswered Question
Feb 28th, 2008


i have the following scenario. i want to create a 100Mbos eompls VC between 2 NPEs:


since the eompls VC is created between NPE loopbacks and i have 7 ospf POS point-to-point links between the 12ks, ospf will load-balance based on destination. because of this all traffic from this VC will pass through one of the POS interfaces. i can't have this because all POS interfaces are at 60% utilization.

i was looking at XR link bundling and restrictions say:


"Load balancing (the distribution of data between member links) is done by flow instead of by packet. Data is distributed to a link in proportion to the bandwidth of the link in relation to its bundle."

from the first part i gather that the bundle will behave something like my 7 ospf parallel links. the second part i don't quite get: does that mean that it will allocate high-BW flows to the least used links?

please advice.


I have this problem too.
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mheusing Wed, 03/12/2008 - 06:01


As far as I know this means something different than what you suspect. From the same document:

"Different link speeds are allowed within a single bundle, with a maximum of four times the speed difference between the members of the bundle"

As such you could have STM4 and STM1 bundled. The STM4 link will get 4 times the traffic of the STM1 link.

Load sharing/balancing in a bundle does not look for average utilization.

Regards, Martin


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