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Sniffing Phone Packets

ghartline
Level 1
Level 1

All -

I'm needing to find a way to see the raw XML getting sent to the phone. Does anyone know of a way that allows me to (a) debug the screen such that I see the text getting sent to it, or (b) essentially span the third port of the phone so I can sniff packets the phone sends to itself?

Thanks.

Grant

8 Replies 8

Run a packet sniffer on the PC that is daisy-chained off the phone. The 'switch' inside the phone actually behaves more like a hub and all of the traffic to/from the phone is present on the computer network connection. Even if the phone traffic is assigned to a different vlan, it shows up on the computer port without any vlan tagging. This includes broadcast traffic on the phone vlan.

I prefer Ethereal for packet sniffing. Its freeware at www.ethereal.com

Thanks for the reply. I can launch a sniffer and see packets between the phone and Call Manager (or between the phone and my PC or between the phone and some other device, etc.). What I can't see, though, are packets that the phone sends to itself, such as the xml displayed on the screen of the phone after pressing the "settings" button. Any magic way you know of to make that happen?

Thanks again.

Grant

I believe all of thats internal to the phone. Some of the other buttons though do hit the CM web server for their xml - for example, 'services', 'directories', 'info'.

-Chris

I do not agree with this. I have a sniffer running on my PC which is attached to an IP phone, and the only traffic I see is on the "Data" VLAN. No packets from the "Voice" VLAN are making their way to my PC, including broadcasts.

Hi Ghartline,

I agree to you that RTP packets are pretty visible using any sniffer.

If i use a Soft IP Phone (PC based) and when i call this number, i can see the RTP packets coming to my machine.

But when i use Hard Phone [Cisco IP Phone 7960] connected to my PC using access port in sequence it dont show me any RTP Packets.

I have seen multiple articles on the net saying that RTP packets are forwarded to the PC for the troubleshooting purpose but somehow any sniffer is unable to sniff it.

Is some problem with the sniffer.. or i need to do some changes in my setup.

??????????

I dunno; you might try making certain that your sniffer is running in promisuous mode (which rules out Network Monitor). I've always just seen them; and in fact I see packets from my host twice; I presume once as the packet leaves my NIC and again when it leaves the phone toward the switch.

None of this, though, was the point of my original post. What I'm needing to do is sniff packets that stay internal to the phone, when you browse the Settings button for example. An alternative is the ability to run debugs on xml post events, etc. like the ones that are available the SIP version.

Anyone know of a way to run basic debugging or gain console access to phones running Skinny code versions?

Grant

Hi Grant,

Are you interested in looking at the XML going to the IP phone when using XML services.

There is a service emulator tool from Cisco , may be that will help you.

You can find it on cisco site or on IPNetworkers site under forums , Cisco CallManager - IP Phone Services Development.

Hope this helps.

-Kamal

Oops i forgot to post the link .

Here it goes :http://www.iptnetworkers.com/forum/category-view.asp

-Kamal