sundance-communications.com/forum Forums TDM Business Telephone Systems Inter-Tel Telephones & Systems VOIP monitor

Hi, I was told that Inter-Tel VOIP uses the standard implementation of RTP to handle audio streams. This gave me an idea for monitoring VOIP calls in our call center. Without solving the details here I would just like some opinions on whether this is feasible or what the major obstacles might be.

There are a few open source RTP to WAV type tools. It is also within my capabilities to create such a tool. Either way I could run one as a service application on each of our Call Center PC's and instead of connecting PC directly to the LAN I could hang it off of the PC Ethernet port on our 8622 IP sets.

If I can then use the PC port to monitor the traffic on the Network ethernet port of the IP set then I very likely will be able to record and save all VOIP calls involving a particular agent.

I believe the two ethernet ports on an 8622 set currently work as a switch such that packets to and from the IP phone itself are not mirrored onto the PC ethernet port. Is this correct? If so, is it possible to have all ethernet packets mirrored onto the PC port?

Any other thoughts or suggestions? If I solve this I will gladly detail the solution for anyone interested.

It's a good idea and should not be that hard to work out, though you'll be eating some disk space.

If the firmware version on the fone is up to date (ver 2.102), then you can put the ports on the fone into mirror mode. You can http to the fones on port 8080 to check f/w versions, you'll need the username and passwords from yer local vendor.

Wow, that's great to know. Our phones are 2.0.2. I'll find out about upgrading.

I have not yet been able to successfully capture and decode RTP packets but I have been told by an Inter-Tel engineer that their use of RTP and RTCP does not include call set up info such as ANI, DNIS, agent ID, direction, etc. This is only available through OAI.

There is a particular vendor who's VOIP monitoring product, which is very nice, depends on capturing all of this information soley through network capture of RTP and RTCP. They claim this works with most other vendors but apparently this won't work with Inter-Tel.

They are correct. The RTP/RTCP packets are only voice packets, no call info is sent/received via RTP. Call setup is sent via TCP port 5566, but I'm not sure you are going to get what you are looking for with that either. Keep us posted.

Finally put an IP set in monitor mode today and captured packets with wireshark. Can't tell yet which TCP based protocols I am seeing yet but when I look at the TCP stream represented as ascii I can easily see in clear text:

- Outbound # dialed
- Extension # and description text
- Inbound hunt group name
- Inbound transfer-from extension number and name
- Inbound Caller-ID name
- Trunk #
- Agent login - Agent ID and hunt groups affected
- Agent logout - Agent ID

The next step would be to try to determine that this information is actually in a TCP protocol sent to the IP phone for call control not specific to the VOIP stream per-se and whether I am merely finding the text intended for the LCD display.

Then to figure out how to dissect that protocol.

Based on my packet captures we have a VOIP call recording / QA software vendor willing to customize their solution for us. They do not intend nor want to use the OAI port. I have a question - is this a licensing or intellectual property issue for Inter-Tel - for us to do call reporting / qa based on decoding packets sent between IPRC and IP set?

Using Ethereal and Audacity you can do this. Ethereal (now Wireshark) will capture the RTP packets for decoding. Audacity will make the actual WAV file. Both freeware. G.729 will not work, only G.711 is possible.