There are times when you would like to forward a call coming into your gateway out to PSTN before it goes to Call manager. Reason could be WAN outage to Call managers or Call manager down situation. This is how you can route out an incoming call out of the gateway. Let suppose the mainline [...]
Archive for the ‘Gateways’ Category
Hair-pinning Or redirecting a call from Gateway
Posted: January 22, 2012 in Call Manager - CUCM, CME, Gateways, H323Tags: H323, h323 Redirect, Hairpinning Redirect, hairpinning VOIP
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Scenario#34 – Cannot make International Calls from US gateway
Posted: August 2, 2011 in Call Manager - CUCM, H323, Real World ScenariosTags: Cisco Cal manager, H323 gateway, International call failes, Translation rules
One of our customer has multiple sites across the globe including sites in UK and US. Their initial design was to send all UK calls from US over a SIP trunk to break out from a UK gateway for LCR (least cost routing). For some reason they stopped using that trunk and configured local dial [...]
Scenario#32 – SIP Calls drop after 75 minutes
Posted: July 21, 2011 in Call Manager - CUCM, CUBE - Border Element, Features, H323, Miscellaneous, Real World Scenarios, SIPI had an interesting case where SIP calls over a SIP trunk were dropping after like 75 minutes. The duration was not confirmed as sometimes it use to drop even before 75 minutes. I looked into few CCSIP debugs (debug ccsip messages) and found that the ‘BYE’ message was actually coming from our end (Call [...]
Scenario#31 – Calls over ICT have delayed Voice
Posted: July 6, 2011 in Call Manager - CUCM, H323, Real World ScenariosTags: Delay over Intercluster trunk, Enable Outbound FastStart, H245 Delay, ICT trunk, Voice delay over ICT
I had an interesting case last week where calls over ICT trunk would connect but then either party will not hear each other for 8-10 seconds. The issue was first reported from US users trying to reach UK users over an Inter-cluster trunk (Non-GK). Both clusters had two call managers version 8.0.3. The whole issue [...]
Applying QoS for Voice Traffic
Posted: April 21, 2011 in Call Manager - CUCM, Gateways, H323, MGCP, Miscellaneous, SIPTags: QoS, RTP, Service-policy, Voice, Voice QoS
QoS is very important for Voice traffic which is delay sensitive. I won’t go into details of QoS over here and will just explain the configuration we normally use on a Voice gateway for QoS. class-map match-any Voice-RTP match ip precedence 5 match ip dscp ef match ip rtp 16384 16383 class-map match-any Voice-Cntl match [...]
Scenario#29 – Interworking error -0x80FF
Posted: February 10, 2011 in Call Manager - CUCM, Features, Gateways, H323, Media ResourcesTags: Transcoder MTP 0x80FF Interworking
I came across this issue with one of our customer last week where a call was coming in to receptionist at Site ‘A’ but she was not able to transfer the call to someone at Site ‘B’. They had Centralized deployment and all phones on branch sites were registered to Central site. The call was [...]
Scenario#27 – RightFax Server not working – MGCP
Posted: October 14, 2010 in Call Manager - CUCM, MGCP, Real World ScenariosTags: mgcp rtp payload-type, RightFax Server MGCP
I had an interesting scenario where customer logged a case with us regarding their RightFax server not working. Those of you who don’t know what is a RightFax server can read about it here. When you dial the fax number from outside, it reaches the gateway and you hear one ringback and then a fast [...]
DSP, PVDM & Media Resources
Posted: August 25, 2010 in Call Manager - CUCM, Gateways, H323, Media Resources, MGCP, Miscellaneous, SIP, VG224Tags: Codec Complexity Flex mode, Conference DSP, DSP Resources PVDM, PVDM2-16, PVDM2-32, PVDM2-48, PVDM2-64, PVDM2-8, Transcoding DSP
The Cisco High-Density Packet Voice Digital Signal Processor (DSP) Module (PVDM2) enables Cisco Integrated Services Routers to provide high-density voice connectivity, conferencing, and transcoding capabilities in Cisco IP Communications solutions. PVDM stands for packet voice DSP module; it is the Cisco product name for the module that provides digital signal processing resources to a system. [...]
Scenario#23 – Fax Issues for ATA
Posted: August 19, 2010 in Gateways, IP Phones & ATAs, Real World ScenariosTags: Fax Problems ATA, fax protocol cisco, fax protocol none, fax rate disable, fax relay
Fax machines connected to ATA were not working. The first thing I checked on the gateway…is fax-relay was being used or fax protocol cisco was configured? Fax-relay is NOT supported by ATA. This is what I found at the Voice gateway: voice service voip allow-connections h323 to sip allow-connections sip to h323 allow-connections sip to [...]
