Detecting internal SIP calls in CUCM

[pandiarajan.it21]

Hello,

In our office lab, we have one gateway and one CUCM.

Will all the SIP calls go via Gateway or only external calls go via gateway ? "External" I mean the SIP calls made to other regions and PSTN calls. 

My understanding is when an internal SIP call (The target user agent is also connected to the same CUCM) is placed, the CUCM redirects to the target user agent and the SIP call doesn't go via gateway. Is my understanding correct?

In this case if we want to detect a call in CUCM, is there any CLI commands and SNMP MIB OID to follow?

Thanks,

Pandi

[Brandon Pierce · Accepted solution]

Calls don't use gateways unless they are routed that direction via a Route Pattern which means they are leaving the system.  If you want to see calls just use the CDR feature or pull logs from RTMT and look for all the SIP INVITE messages to other phones.

[Brandon Pierce]

There are third party applications out there that can pull CDRs and organize them for you as well.  They are programs you have to pay for but would accomplish what you are looking for without the need to do everything manually.  Then again, if you search CDRs by the DNs you can easily find what you want that way as well in a less pretty GUI.

[pandiarajan.it21]

Hi Brandon, thanks for your answers. We are also trying out the samething. We do process CDRs, but we are new to SIP.

[Andrew West]

To add to what Brandon said both RTMT and DNA (Dialed Number Analyzer) are two tools you should be using a lot when you are trying to get a better understanding of your call flows. 

[pandiarajan.it21]

Thanks a lot Brandon (+5).

So, you mean generally organizations don't route the internal calls to the gateway. This is why we need to put a prefix "0" or "9" to make outbound calls right?

Also for call detection, will CDR have protocol details (SIP - TCP/UDP) and codec details like g711?

Thanks,

Pandi

[Brandon Pierce]

The CDRs combined with the CMRs will show you everything from called/calling to IPs to codecs and much more.  Generally, the whole 9 or 8 to dial out is just a standard as most people are used to dialing in that fashion and hearing a second dial-tone.  You could easily set a normal route pattern to just use standard dialing as whatever you prefix gets stripped before it leaves the CUCM anyways.