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catalyst 500, voip, dropped calls

Are there any known issues with the Catalyst 500 series and dropped VOIP calls? We are having repeated problems, and our provider keeps pointing back to the switch.

We are using a CE 500 24-PC and LG phones. Switch software has been upgraded, multiple different Smartport configurations have been tried, and the switch itself has been swapped out with a second 24-PC.

Any input would be greatly appreciated.



Re: catalyst 500, voip, dropped calls

What diagnostics have you/your provider done that leads you to believe this is a switch problem?

Have you collected any traces? What are the precipitating circumstances just prior to the drop (if any)?

Have you tried any other (non-E500) switches?

It could be something as simple as needing Frame-Relay taffic shaping on the interface(s) to your WAN.

More details would be helpful. I've used E500s in a variety of roles and configs, all have worked without a hitch.

Good Luck


New Member

Re: catalyst 500, voip, dropped calls

Are your phones randomly rebooting as well? Check to see when they last registered. If possible I would use a 3550 or 3560 power switch to see if the problem goes away.

The logging and diagnostics on the Cat 500 may point to LAN issues; unfortunately, there is no syslog built in, so power-off loses the log.

If you are using non-Cisco phones, you may have issues since not all IP phones use the same TCP/UDP ports for control and voice streaming. In other words, you may need to adjust your WAN QoS on the routers.

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