[c-nsp] VOIP/QOS

[Paul Stewart]

Hi there...

I've finally had a few minutes to start exploring our entire network
with the hopes of prioritizing/optmizing VOIP based traffic.  After a
lot of reading, I'm not sure which methods to use.  My first question is
in regards to what common practice is with everyone on the list.  My
issues are not around congestion (generally speaking) - I want to make
sure however that any SIP based traffic flows arrive before everything
else does basically...

At this point, I've figured that "ip precedence" will help me with this
.. Am I heading down the wrong path?

Here's a config I'm workig with this morning (cisco 3640 at a customer
site that is using SIP):

class-map match-any VOIP
  description SIP Prioritization
 match protocol sip
 match protocol rtp
 match protocol rtcp
!
!
policy-map SIP
 class VOIP
  set ip precedence 2

interface FastEthernet0/0
 description WAN 1
 ip address xx.xx.xxx.98 255.255.255.248
 ip nbar protocol-discovery
 ip route-cache flow
 load-interval 30
 speed 100
 full-duplex
 service-policy input SIP
 service-policy output SIP


Is this wrong?  Seems a little too simple and/or does this even
accomplish what I want to do?..;)  any input would be appreciated...
Sorry if this is QOS 101 but we've never had a reason to worry about QOS
before and now I'm concerned with real-time VOIP etc. that we shouuld be
concerned...

Paul Stewart
IP Routing/Switching
Nexicom Inc.
http://www.nexicom.net/