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New Member

Fragmentation for IDSN DDR

I am trying to set up a VoIP link between my central site (2 * CCM + PSTN Gateway) and a small office, using one ISDN BRI (but not necessarily the 2 B channel) so that we can have IP Phones on this office.

How can I configure fragmentation on the DDR link to minimize the serialisation delay?

Doesn't anyone have sample configuration with multilink PPP on such a case, or do I have to set the MTU size on the remote PC's / network devices?

Cisco Employee

Re: Fragmentation for IDSN DDR

You would need to use the ppp multilink interleave command. Check out the following URL:

Although I am pretty sure with ISDN MLPPP and 2 B channels bonded that you can't use ip rtp header-compression. If you have only 1 B channel in the MLPPP bundle then it should be fine to use this.