CHANNEL-ASSOCIATED INTEREXCHANGE SIGNALING

1. presented by:
Yogeesh M
M.tech/DCN
ID:1DA17LDN08
Technical Seminar
on
CHANNEL-ASSOCIATED
INTEREXCHANGE SIGNALING

2. WHAT IS INTEREXCHANGE SIGNALING..?
• Exchange of control information between two switching units in a
telecommunication network.
• CAS  Per Trunk Signaling
• There are three types of inter-exchange signaling are :
1. Supervision signals.
2. Address signals.
3. Tones and Announcement signals.
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3. INTEREXCHANGE SIGNALING EXAMPLE…
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4. Phase – I (S1-A-B)
1) S1 sends S2 number to exchange A.
2) When Exg. A receives complete
digits
 It seizes T1.
 Send seizer signal on T1.
3) Exg. B responds with Wink signal.
4) Exg. A sends digits and cuts through.
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5. Phase – II (B-C-S2)
1) When Exg. B receives complete digits:
 It seizes T2.
 Send seizer signal on T2.
2) Exg. C responds with Wink signal.
3) Exg. B sends digits and cuts through.
4) Exg. C sends ringing signal to S2 and
ringing-tone on T2.
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Ring

6. Phase – III (S1-S2, Billing and Termination)
1. When S2 answers
• C cuts through a path between T2
and S2.
• Send answer signal on T2 & Exg. B
repeats the signal on T1.
• Conversation begins.
2. Assume called party S2 hangs up
first.
• Exg. C sends clear-back signal to Exg.
B & Exg. B repeats the signal to A
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Answr.Answr. S/gAnswr. S/g

7. Phase – IV (Link Release)
• Exg. A release its path b/w S1
and T1.
• Sends Clear forward signal to
Exg. B  Release path b/w T1 &
T2.
• Repeats Clear-forward signal to
Exg. C  Release path b/w T2
and S2.
• Then T1 and T2 sends release-
guard signals to A & B
respectively.
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Answr.Answr. S/gAnswr. S/g

8. GROUPS OF INTEREXCHANGE SIGNALS
There are 3 groups exist in CAS.
1. Supervision Signals:
• Line signals.
• Represents events that occur on the trunk.
2. Address Signals:
• Selection signals/digits/register signals.
• Used to indicate the called number.
3. Tones and Announcements:
• Ringing-tone and busy-tone.
• Same as subscriber signal.
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9. ThankYou…