- This topic has 26 replies, 1 voice, and was last updated 9 years, 4 months ago by Zelagio Gomes.
16th May 2004 at 14:50 #38155Ashish GoelGuest
This is Ashish. Can anyone tell me how a call routed to announcement is treated in CCS 7 network.
i will give a scenario :
Suppose i call a mobile subscriber from a landline number and the b party does not answer. Hence the call is routed to an announcement and the ringing tone is ended.
My query is that what messages will be exchanged between A-Exch and B-exch on CCS7 and how the call will be treated : whether it will be an answered call or the call will be put in some other parameter of the traffic reports. If it is not an answered call then why.
Also what are the various release causes sent in the REL message in CCS7.
Ashish Goel20th May 2004 at 10:48 #38156HiteshGuest
1. Exhange A will send IAM meassage to Exch B
2. Exchange B subscriber will start ringing & Exch B will send ACM (Address Complete) meassage to B
3. As exch B get ACM it will switch Ring Back Tone to subscriber A
4. After Ring timeout Exch B will send REL (Release) to Exch A with cause B party not replying.
5. As Exch B get REL message it will disconnect RBT & play apprpriate announcement (Number U dialled is not replying)
There are many REL causes (e.g Busy,No answer,congestion,unalloted numbere..etc..etc),Details can be found in ITU-T specs.20th May 2004 at 14:18 #38157Jack SparrowGuest
At what Conditons and Why the Announcements given from HPLMN and VPLMN ?
Jack Sparrow24th May 2004 at 15:50 #38158Ashish GoelGuest
As you have written after the REL message the call is routed to announcement and an appropriate announcement is played. I suppose that moment the REL message is received by A side it will release the circuit and the call will be ended. Then how the announcement is heard after the release message is received.
Ashish Goel24th May 2004 at 17:05 #38159RoameoGuest
When the Terminating MSC recives the REL it sends an IAM to the announcement number. The REL is not relayed to the A-party.
R….25th May 2004 at 09:29 #38160HiteshGuest
Announcement is played by Exch A ,not by B ie why after the release of trunk between Exch A and Exch B annc. can be listened by subscriber A.25th May 2004 at 09:34 #38161RoameoGuest
I am sorry, it was not the Terminating but the originating MSC.
R….25th May 2004 at 09:37 #38162Ashish GoelGuest
The announcement is played on CCS-7 trunks by A side. However if we make a call form PSTN (Landline) to a mobile subscriber then the ann. for mobile are not loaded into the PSTN switch but they are heard from B side i.e the Mobile switch. Can u discuss this issue.
Ashish25th May 2004 at 10:13 #38163RoameoGuest
I still feel the T-Switch is involved as part of the announcement since if A(Airtel) calls B(BPL-Mobile) and B is not reachable we get announcement saying BPL-Mobile subscriber is not available.
Could you please confirm if the T-Switch is not a party how this announcement can be played by the Airtel originating MSC?
Anant25th May 2004 at 16:09 #38164Jack SparrowGuest
BPL Announcement Played by BPL.Not by AIRTEL.
So Ex-B is the Party Who provides Announcement.And this is before GMSC Releasing the call.
Whoever Calls GMSC is The Handling Party.
Are you working in APL/AIRTEL in TamilNadu ?
Then what is this T-Switch…?
Rgds25th May 2004 at 16:19 #38165RoameoGuest
By T-Switch i meant the terminating switch/MSC.
Rgds25th May 2004 at 16:41 #38166Jack SparrowGuest
Anant…Are you from BPL- Cochin ?
Rgds25th May 2004 at 16:42 #38167RoameoGuest
Nopes.25th May 2004 at 16:43 #38168Jack SparrowGuest
Are u in India and where ?
Rgds26th May 2004 at 13:05 #38169AndrewGuest
This topic is of interest to me aswell but I must admit I am lost guys 🙁
Are you guys suggesting that the GMSC after receiving a REL message from the VMSC connects the calling party i.e. A party to an announcement device?