TVOICE – UCM Traces + Alarms: Demo Part 4
For this demo we saw some more RTMT traces for intersite calling using various types of gateways. Some high points, fundamentals and further reading below…
What is a B Channel?
What is a D Channel?
‘Busying Out B Channels’
* I remember this being covered before and it is long winded to setup. It also eats up your trunks!
‘Dump DA Information’ (Dumping Digit Discard Instructions and Dialing Patterns)
Each Cisco CallManager dial plan configuration has called party transformation information, that includes discard digit instructions (DDIs). Dialed Number Analyzer allows you to view the DDIs that are specified for the Cisco CallManager dial plan that you are analyzing.
The tool also allows you to view all the dialing patterns that are associated with gateways and phones that are configured in the Cisco CallManager dial plan that you are analyzing. Use the following procedure to view DDIs or dialing pattern information that is specified for a dial plan.
Play with traces and debugs in a lab environment!! LEARN LEARN LEARN!
IOS Debugging – H.323 + SIP
‘show dialplan number 911′ – Great command to show what dial-peer is used on the called number.
*’Macro Exp’ = Expected destination pattern for this dial peer.
debug cch323 h225
debug h225 q931
debug h225 asn
To display ASN1 contents of RAS and Q.931 messages, use the debug h255 asn1 privileged EXEC command. The no form of this command disables debugging output.
H.323 is stable and popular. SIP is however viable for PRI/PSTN Gateways.
Time that Cisco Unified Communications Manager should wait before retransmitting the PRACK request.
While the PSTN provides inband progress information to signal early media (such as a ring tone or a busy signal), the same thing does not occur for SIP. The originating party includes Session Description Protocol (SDP) information, such as codec usage, IP address, and port number, in the outgoing INVITE message. In response, the terminating party sends its codec, IP address, and port number in a 183 Session Progress message to indicate possible early media.
CONDITIONAL DEBUGGING – CALL FILTERS, MATCH LISTS + DEBUG CONDITION