VoIP and Packet Size

I've been asked to prioritize VoIP traffic for a customer that uses a private wireless network managed by another contractor for transport from the remote sites to headquarters. All VoIP traffic enters the network from 1711s at the remote sites (interface Fa2, VLAN 10). If I classify these packets, apparently the transport folks will offer expedited forwarding.

Is the best way to accomplish this by setting diffserve to ef for these packets?

Once these packets arrive at HQ, will all the Cisco routers and switches automatically prioritize these packets or do I need to configure PBR on every device in the path for expedited forwarding?

Is it advisable to segment packets from competing streams to reduce latency? If so, can this be accomplished by simply setting MTU to something in, say, the 200 - 300 Byte range?

Reply to
Bob Simon
Loading thread data ...

ask the WAN guys - but yes, EF is the normal way to do it.


or do I need to

Use QoS setup instead.

i suggest you look at some of the Cisco Voip / IPT / QoS best practice (even if the Voip traffic is from someone elses kit) - try here....

formatting link


And even if you do, the minimum IP MTU is 576.

However, better to not break other things, and jitter from other packets is usually only an issue where the link speed is 1 Mbps or lower.

in those cases you can use L2 fragment schemes on a link by link basis.

Reply to

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.