Noise is an analog issue. Are the router ports FXS, FXO, or E&M? If not then there's nothing you can do on the router.
If they are analog ports you need to figure out where the noise is being injected. A butt set is the most common way: replace the router with the butt set and see if you hear the noise from either "side" of the router: ingress and egress.
While very unlikely if you don't hear the noise on either of the interfaces connected to the router but you do hear it when the call passes through the router it is possible there is a hardware failure in the VWIC/VIC or the PVDM. I had a DSP go bad once which resulted in hissing on the call. Again, rather unlikely.
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...