SIP Phone-->CUCM-->H.323-->PSTN Detailed call flow

[prakashsatya]

Hi ,

i need a brief call flow messages on below call flow scenario .

SIP Phone -->CUCM-->H.323-->PSTN

1.what are all the messages between SIP Phone and CUCM

2.messages between CUCM & H.323

3.messages between H.323 & PSTN 

i am being  more specific on first 2 parts .

Regards,

Satya 

[Sreekanth Narayanan]

Satya, SIP and H.323 are both open standards so you should be able to see the call flows by googling for them.
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cuipph/7960g_7940g/sip/8_0/english/administration/guide/8_0/sipaxb80.pdf
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cata/186_188/3_0/english/administration/guide/h323/h32330ad/h3288APH.pdf

[prakashsatya]

Hi Sreekanth ,

Thanks for your kindly reply.
I am more specific on what messages from CUCM to H.323 , when CUCM receives call from a SIP Phone ?

Regards,
Satya

[prakashsatya · Accepted solution]

found a very useful link

https://community.cisco.com/t5/collaboration-voice-and-video/unified-communications-call-flow-in-an-enterprise-network/tac-p/3142772#M5781