Here's the test environment setup. Location A's PBX is connected to the FXO ports of 2600 series router. Location A is connected to Location B through 64 Kbps. Location B's PBX is also connected to a 2600 series router. Trying to understand how QoS works, I'm using g.729 r8 codec and have configured two dial-peers on either side and connected two analog phones. What parameters should I use with "ip rsvp bandwidth command"? The serial interface is enabled for fair-queuing. I tried "ip rsvp bandwidth 48 16" command. When I place a call, the routers display that a reservation event 1 occurs. But there is jitter during the call when I am pinging the router B's interface with large packets 1500. The jitter gets less when I stop the pings. When I change to "ip rsvp bandwidth 48 32", the quality gets better but there is no reservation event on the router. My question is why? Also there should be no jitter, the whole point of QoS is that if the resources are not available to satisfy the QoS profile parameters, then don't complete the call. I'm trying to get to the bottom of this. Anyhelp would be appreciated. Thanks in advance.
Thanks for your reply. I'm using 12.1.6. and yes I have the dial peers with req-qos configured. I went back and changed the ip rsvp bandwidth to 48 24. I have another question for you. Can I use priority queue instead of LLQ? I thought of creating a access list to allow udp gt 16384 and get the priority list to use that access list to assign the priority of high leaving all other traffic normal. I was searching for the LLQ commands. Seems like it was no enabled by default or if was it wasn't working. So, I went ahead and tried the PQ with the same scenario. Now my voice quality is definitely clear. Am I on the right track? Thanks for all the help.
You're on the right track. The thing is, LLQ *should* automatically do priority queueing for voice and with RSVP and fair-queing turned on the serial interface, LLQ *should* automatically get turned on (although I don't know if the commands are visible in the running config). See if the command "ip rsvp pq-profile voice-like" is in your config. You might try adding it and see if that turns on LLQ.
If that doesn't work, you can try explicitly configuring LLQ (I think there's an example at that same url). It does exactly what you've described--priority queue for voice, wfq for data.
SIP traces provide key information in troubleshooting SIP Trunks, SIP
endpoints and other SIP related issues. Even though these traces are in
clear text, these texts can be gibberish unless you understand fully
what they mean. This document attempts to br...
Please find the attached HTML document, download and open it on your PC.
This provides an easy to use form where you simply answer a few
questions and it will render the proper jabber-config.xml file for you
to copy/paste. There is built in logic to verif...
CUCM Database Replication is an area in which Cisco customers and
partners have asked for more in-depth training in being able to properly
assess a replication problem and potentially resolve an issue without
involving TAC. This document discusses the bas...