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Static on Dial Tone

Has anyone ever heard of static on a dial tone? My dial tone is fine with:

- IP phone to IP phone

- IP phone to PSTN

But when I call my PTP to a PBX system, I get static in the ring tone. Is that static coming from the PBX or from the Cisco side (router, switch, phone, etc)


The static I am getting on the line is only incoming from the PBX...

could it be compression? I'm on 7.11u

update 2:

ok, figured it out. Looks like the clock source was out of whack. While doing our testing, we were unplugging and plugging in T1s to different CMM ports and we think the clock source got off or not in sync. After resetting both ends of the T1's.. they synced and the static went away.

New Member

Re: Static on Dial Tone

This may be because of frame slips on the PRI caused by a clocking mismatch