Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

Static on PRI calls

Problem: Some phone users both Cisco & Turrets are experiencing static when they are having conversation. Again this static is totally sporadic,

We have tried changing turrets but no luck, and IPC says that it is the phone system.

Following is the time-line as the events occurred.

December-14: Checked to slip secs on both T-1 and E-1 and noticed some on T-1 interface, and fixed slip secs by adjusting clock source. After the changes there were no slip seconds and thought this would fix the issue

December-20: This time took help from TAC, and they suggested and which we did to Upgrade IOS 12.4(5) which has new DSP code 4.4.20 and upgrade the PVDM2.

December-26: We are still having same issue, and it this point we asked Verizon

January-2: Verizon said that their circuit is clean with no problems, coincidentally users said he did not hear any static after the test. So we thought that Verizon testing kind of fixed that static, but not

January-9: We are having static again


Re: Static on PRI calls

You have to Upgrade IOS latest versions. This may be because of frame slips on the PRI caused by a clocking mismatch.

CreatePlease login to create content