[cisco-voip] "Random" Call drops

[Dietmar]

Have you enabled H.323 inbound fast start on CUCM? If yes, please try without. 
There was a bug some time ago that caused such behavior.


Dietmar


On Tuesday 06 January 2009 08:50:47 William Roy wrote:
> We are seeing random call drops on calls made from an CUCM site via the
> PSTN to another site where the phones are connected to a Siemens PABX. The
> CUCM is 6.1.1-200-3 and the calls are being made via a 3845 - h323 gateway
> connected to an E1 telco service with switchtype primary-net5. The random
> call drops  have not been reported to any other external numbers which go
> via the same E1, only to this specific site with the Siemens Pabx. The
> problem may also have started when the CUCM phone system was reconfigured
> to append a carrier access code to external numbers to swap the service
> provider for cheaper rates. We are currently seeing if sending calls via
> the default carrier fixes the issue. I managed to capture a debug isdn q931
> of a call dropping. The Cisco gateway is receiving the following disconnect
> code: "   Cause i = 0x80FF - Interworking error; unspecified". Looking up
> the cause code - the point of origin 0x80 means that this was from the
> router, why would the router receive a disconnect from itself?
>
>
> 464020: Jan  6 13:15:12.130 WST: ISDN Se0/0/0:15 Q931: TX -> SETUP pd = 8 
> callref = 0x415B Sending Complete
>         Bearer Capability i = 0x8090A3
>                 Standard = CCITT
>                 Transfer Capability = Speech
>                 Transfer Mode = Circuit
>                 Transfer Rate = 64 kbit/s
>         Channel ID i = 0xA98387
>                 Exclusive, Channel 7
>         Calling Party Number i = 0x0081, '35525'
>                 Plan:Unknown, Type:Unknown
>         Called Party Number i = 0x80, '18875093114171'
>                 Plan:Unknown, Type:Unknown
> 464021: Jan  6 13:15:12.214 WST: ISDN Se0/0/0:15 Q931: RX <- CALL_PROC pd =
> 8  callref = 0xC15B Channel ID i = 0xA98387
>                 Exclusive, Channel 7
> 464022: Jan  6 13:15:13.974 WST: ISDN Se0/0/0:15 Q931: RX <- ALERTING pd =
> 8  callref = 0xC15B Progress Ind i = 0x8488 - In-band info or appropriate
> now available Progress Ind i = 0x8082 - Destination address is non-ISDN
> 464025: Jan  6 13:15:19.114 WST: ISDN Se0/0/0:15 Q931: TX -> ALERTING pd =
> 8  callref = 0xB0D2 Progress Ind i = 0x8188 - In-band info or appropriate
> now available 464026: Jan  6 13:15:22.830 WST: ISDN Se0/0/0:15 Q931: RX <-
> CONNECT pd = 8  callref = 0xC15B 464027: Jan  6 13:15:22.834 WST:
> %ISDN-6-CONNECT: Interface Serial0/0/0:6 is now connected to 18875093114171
> N/A
>
> 464028: Jan  6 13:15:22.834 WST: ISDN Se0/0/0:15 Q931: TX -> CONNECT_ACK pd
> = 8  callref = 0x415B
>
> 464063: Jan  6 13:16:34.953 WST: ISDN Se0/0/0:15 Q931: RX <- DISCONNECT pd
> = 8  callref = 0xC15B Cause i = 0x80FF - Interworking error; unspecified
> 464065: Jan  6 13:16:34.953 WST: %ISDN-6-DISCONNECT: Interface
> Serial0/0/0:6  disconnected from 18875093114171 , call lasted 72 seconds
>
> 464066: Jan  6 13:16:34.953 WST: ISDN Se0/0/0:15 Q931: TX -> RELEASE pd = 8
>  callref = 0x415B 464067: Jan  6 13:16:34.973 WST: ISDN Se0/0/0:15 Q931: RX
> <- RELEASE_COMP pd = 8  callref = 0xC15B
>
>
> Regards,
>
> Wil