Troubleshooting Notes #1

Outside Dial Tone Played at the Wrong Time

• If multiple patterns exist with the same first digit and at least one of the patterns is not configured to provide outside dial tone, outside dial tone is not played unless all the remaining potential matches are configured to provide it.
• Fix 1: Check the box on the 911 route pattern that tells it to play outside dial tone.
• Fix 2: Change the 911 pattern to 9.911 instead and check the box that tells it to play outside
  dial tone (although 9.911 is already included as part of 9.@).
• A good way to isolate the problem is to view the Route Plan Report in Cisco CallManager Administration (Route Plan > Route Plan Report).

Call Forward All (CFA)

• For calls within a cluster, use the Forward Maximum Hop Count service parameter (Service > Service Parameters > select a server > Cisco CallManager) to end a forwarding chain after a specified number of hops
• Use MaxForwardsToDn and StopRoutingOnUserBusyFlag to prevent routing loops that traverse other clusters or legacy TDM equipment.

Called and Calling Party Transformations

1. The External Phone Number Mask on the original calling device (when specified on a route pattern or translation pattern by the Use Calling Party’s External Phone Number Mask checkbox.)
2. A translation pattern
3. A route pattern
4. A route list using route group details
5. Transformation on the terminating device

Methodology for Resolving Call Routing Problems

1. What calling device is having the problem (phone, gateway, CTI ports, Voicemail ports, etc.)?
2. What is the dialed number as dialed by the user or sent by the gateway?
3. What calling search space (and corresponding partitions) are being searched?  Pay attention to the different line/device CSSs that come into play.
4. If a match is made (important word = IF), what pattern is matched?  What partition does that pattern belong to?
5. Is a translation pattern being us?  If so, where is it redirecting the call?
6. Are there any DDIs taking place?
7. If the route pattern goes to a route list (i.e. 99% of patterns), check the route list for digit manipulation being done at that level.
8. If you’re sure the outbound call is hitting the gateway, use my best friends:
   debug isdn q931
   debug voip dialpeer (H.323/SIP only)
   debug voice translations (H.323/SIP only)

Random Notes

• The acronym DDI refers to “digit discard instruction” and not “direct dial in” which is commonly used to refer to direct inward dial (DID) numbers in some countries.