ā07-11-2013 10:53 AM - edited ā03-16-2019 06:20 PM
Guys, we all know about debug isdn q931 output message, I've 4 doubts in that. (which are in highlighted form in the attached snapshot)
& i = 0x80 (Line 12)
Please check the attached snapshot for your reference.
Thank you in advance.
ā07-12-2013 03:48 AM
Hi Mohit,
Below is the required information:-
1). channel id is composed of Bearer capability and the channel (i.e. slot occupied for the call)
for e.g in your case Bearer Capability is = 0x8090A3 and channel is 31 which int turns into 0xA9839F
Here, A398 value is interchanged from the bearer capability and 9F (80+1F) is the hex value of channel no 31 (hex=1F)
2). pd stands for protocol discriminator which means that value is used to distinguish messages for user-network call control from other messages.
for e.g
pd=8 for Q.931 user-network call control messages
pd=9 for Q.2931 user-network call control messages
3). Progress Ind i = 80 means it indicates that tones and announcements are available for that particular call.
various other progress indicaiton is as below:-
4). calling party & called party information is as below:
Ā· 80 the router
Ā· 81 the private network near the local user (possibly a local private branch exchange [PBX])
Ā· 82 the public network near the local user (local telco switch)
Ā· 83 the transit network (in the ISDN cloud)
Ā· 84 the public network near the remote user (remote telco switch)
Ā· 85 the private the network near the remote user (possibly a remote PBX)
Ā· 87 the international network
Ā· 8A a network beyond the internetworking point
ā07-12-2013 05:27 AM
Hi Nishant, thanks for your quick response.
Channel ID is composed of Bearer capability + Channel
Bearer Cap -> 0x8090A3 represents Voice/Speech call (G711 - A-law)
For e.g. In our case Bearer Capability is = 0x8090A3 (which represent that G711 A Law codec is being used) and channel is 31 which int turns into 0xA9839F (how it got turn into this value 0xA9839F, is that a hexa. addition or sort of something)
A398 value is interchanged from the bearer capability and 9F (80+1F) is the hex value of channel no 31 (hex=1F) ?
ā07-13-2013 07:16 AM
Decoding these values require understanding of Q.931:
https://www.itu.int/rec/T-REC-Q.931/recommendation.asp?lang=en&parent=T-REC-Q.931-199805-I
ā07-13-2013 08:17 AM
That is really helpful Paolo, Thanks
ā07-14-2013 04:13 AM
Thank you for the nice rating and good luck!
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