Multilink on Serial Interfaces with different bandwidth??

[shijogeorge]

Hi,

Can I configure multilink on serial links with different bandwidths? I am made to understand that multilink does a per frame load balancing irrespective of the link size and this may chock the lower bandwidth link and drop further packets routed through this link. Is that correct?

If yes, any means are there to override this?

Thanks in Advance

Shijo George.

[Georg Pauwen]

Hello Shijo,

you can specify which load sharing mechanism you want to use, with the interface command 'ip load-sharing per-packet/per-destination'. With CEF enabled, per destination load balancing is the default.

HTH,

GP

[shijogeorge]

Thanks GP,

But here I am configuring ppp multilink with serial interfaces of different bandwidths. Will I be able to configure a multilink to use the higher bandwidth link more?

Thanks!

Regards,

Shijo George.

[amit-singh]

Shijo,

PPP multlink uses its own alogrithm to fragment the packets and do the load-balancing on the links. It uses best effort delivery to achive the proper load-balancing. If your serial interfaces are of diff bandwidth still you can use MPPP. If the bandwidth is low upto a range this will not effect much like an E1 interface with BW 2048 bundled with serial interface 1544 KBPS or 960 Kbps. But if you are bundling a serial interface with async interface, you migh see traffic saturation.

HTH,

regards

[shijogeorge]

Thanks Amit,

My requirement is to bunble two serial interfaces one 2Mbps and the other 1Mbps.

Once the traffic reaches 2Mbps, MPPP algorithm may share the traffic and loads each link by 1Mbps. But once traffic goes above 2Mbps the traffic may again be destributed between the two links which the 1Mbps link can't handle. (I believe the MPP algorith doesnt takes in to consideration the load/bandwidth of links).

Am I correct?

If this is the case also, any means I can modify this behavior?

Regards,

Shijo George.

[amit-singh]

Shijo,

Whatever traffic is there MPPP will try to load-balance it over the 2 links. For instance if you traffic is 400 Kbps, it will be load-balanced equally on both the links.

Now if your traffic is over 2 mbps your 1 mb link gets oversubscribe in this case. We cannot change the algo.

regards,

-amit singh

[shijogeorge]

Thanks a lot Amit

That answers my query!!

Regards,

Shijo George.