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Cannot sniff RTP on same switch

Hello, we are having a problem recording conversations from a cisco IP phone to another on the same switch.

however all external PSTN outgoing & incoming calls are being recorded fine..

we use vlan 1 for data and vlan 10 for voice

we are using a Nice voice recording solution.

We have 2 Core Switches (Cisco 3750's) - with Distribution Switches (Cisco 2950) connected to these.

If the Nice recorder is plugged directly into Core Switch1 it will record RTP between two phones both plugged directly into core switch1 (not best practise) but not between two IP Phones both plugged in one of the Distribution Switches that is connected to core switch1

also with the recorder plugged directly into Core Switch1 there will be no RTP recorded between IP phone to IP phone on Core Switch2 or between IP phone to IP phone on a Distribution Switch connected to Core Switch2.

Here is the config on the core switch:

monitor session 1 source vlan 10

monitor session 1 destination interface [call logger interface]

Thanks in advance

Hall of Fame Super Gold

Re: Cannot sniff RTP on same switch

Hi Monkyboy,

Media traffic between phones connected to the same switch will stay in the switch, so it's normal that you cannot monitor it from another switch.

You can use RSPAN to monitor traffic from a remote port, please see:

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