Callsetup Genl Present

ORIGINATING EXCHANGE ( A- EX ) A-Sub (1)

A-SLMCP Off hook

(2)

A-DLUC

Seizing

(3)

CP

A-GP

Seizure AD

(a) Channel idle

(4)

Seizure AD

(6)

(5)

(7) Set up

(8)

(b) Port A Seized

(9)

1. OFF - HOOK 2. SLMCP DETECTS SEIZURE , INFORM DLUC 3. MSG TO A-GP , C-REG SEIZED 4. GP CHECKS COS , ALLOCATES TS 5. CP INFORMED ( VIA NUC ) 6. CP SEIZES PORT-A & THE CHL 7. DLUC SENDS THE TS to SLMCP 8. TEST OF CONNECTION PATH UPTO SLCA 9. GP ASKS SLMCP TO THROUGH CONNECT PATH FOR DT & DIGITS

ORIGINATING EXCHANGE ( A- EX ) A-Sub

A-SLMCP Dial tone

(12)

A-DLUC

CP

A-GP (10)

(11) Dial tone

IT 1 digit st

(13)

(14) (15)

(16) Set up digit (18)

(17)

digit digit

(19)

Digit Block

10. TOG CONNECTS DIAL TONE

11. SLMCP CHECKS SUBS LOOP

12. DIAL TONE RECEIVED

13. IT ACTIVATED

14. DIGITS CR

15. DECODED DIGITS TO GP

16. DT DISCONN. BY SLMCP

17. DT SWITCHED OFF BY GP 19. DIGIT BLOCK TO CP

18. FURTHER DIGITS IN CREG 20. DIGIT BLOCK STORED IN CPB

(20)

ORIGINATING EXCHANGE ( A- EX ) A-GP (21)

(20)

(23)

B-GP

CP

DIGIT BLOCK

SGC

(24) (25) (26)

SET UP S N SEIZURE BT

(27) (28)

21. COME AGAIN

22. FURTHER DIGITS

23. DIGIT BLOCK TO CP

24. TRANSLATION : ROUTE , ZONE , INDEX

25. IF IDLE B PORT SEIZED

26. SETUP SN

27. SEIZE BT to B-GP & DIGITS 28. PORT B DATA STORED in CREG , in B-GP

ORIGINATING EXCHANGE ( A- EX ) A-GP

CP

B-GP

SET UP (29) (30) SGC

COC (31) (32)

SETUP COMPLETE

SET UP S N

(33) (34) (35)

29. CP SENDS SETUP to A-GP ( With ZONE Index ) 30. A- GP starts COC 31. Evaluates COC if +ve, SETUP GS – A 32. SETUP COMPLETE to B-GPFurther digits direct to B-GP 33. DIGITS in B-CREG 34. B-GP DISCONNECTS COC Loop,O/G TRUNK SEIZED 35. DIGITS ON O/G TRUNK

SEIZURE BT

ORIGINATING EXCHANGE ( A- EX ) A-GP CP B-GP Digits (36)

(37)

Digit Transfer

(38) (39)

Digits Address Complete

Address Complete

(41) (42)

Message flow in the processor Commands, Messages, Reports , Line signals

36. A - CREG receives further DIGITS 37. DIGIT TRANSFER REPORT 38. DIGITS stored in B - CREG 39. DIGITS to B - EX on TRUNK 40. ADDRESS COMPLETE from B - EX 41. ADDRESS COMPLETE from B-GP to A-GP 42. B-GP SETS UP B- GS

(40)

I N - COMIN G CALL

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

A-LTG ( B-EXCH.) Receives SEIZURE SIGNAL A-GP SEIZES A-CREG , Allots TS between A-LTG & SN A-GP Sends SEIZURE AD to CP A- GP (B-Exch) Sends SEIZURE ACK. Signal to B-GP(A - EX) CP ( B-EXCH) SEIZES PORT A, CPB & A-CHR A - GP Sets GS and Connects CR Digits from B_LTG (A-Exch. ) to CR ( B-Exch. ) TOG (A-LTG) (B-Exch.) to ACK. DIGIT CODE to A-Exch. Digit by Digit , CR Reports to A-GP ( B-Exch. ) DIGIT BLOCK A-GP to CP,CP stores in CPB ,COME AGAIN Additional digits in A-CREG, DIGIT BLOCK to CP CP finds out B-Subs PORT (DLU, SLCA), which LTG , B-CHR CP sends SETUP SN TO SGC CP sends SEIZURE PORT B , SEIZURE BD to B-GP(B-Exch.) B-GP SEIZES B-CREG, TS on DLU & SN Side

16.

B-GP sends SEIZURE BD & TS to B-DLUC & B-DLUC sends it to B-SLMCP , B-SLMCP loads TS into B-SLCA

17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27 28. 29. 30. 31.

DIU(dlu) GS DIU SLCA TOG CR DIU(dlu) GS DIU SLCA CP sends SETUP to A-GP (B-LTG no. , B-SUB idle ) A-GP does COC, if +ve sends SETUP to A-GS (DIU to LIU) & SETUP COMPLETE to B-GP B-GP test if +ve, sends RINGING Command to B-DLUC B-DLUC issues RINGING Command & RINGING is controlled by B - SLMCP B-GP sends SETUP B-GS ( TOG to LIU ) for RBT to A-SUB A-SUB (A-Exch.) Receives RBT, B-SUB (B-Exch.) gets RINGING Current & IT activated at B-GP ( B-Exch. ) B-SUB goes OFF HOOK ( B- Exch.) B-LTG tests.

B-SLMCP detects , disconnects RINGING and informs B-GP B-GP disconnects RBT,SETUP GS (DIU to LIU) through B-GS B-GP ( B-Exch ) sends ANSWER Report to A-GP ( B-Exch.) A-GP ( B-Exch.) sends ANSWER Signal to B-GP (A-Exch.) B-GP ( A-Exch.) sends ANSWER Report to A-GP (A-Exch.) A-GP (A-Exch.) starts CHARGING on receipts of ANSWER report Finally Meter data is transferred from A-CREG ( A-Exch.) to CP ( A-Exch. )

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

FOR W A RD

RE

LE AS E

A-SUB GOES ON-HOOK A - SLMCP DETECTS & SENDS CLEAR FORWARD MESSAGE TO A - DLUC A - DLUC SENDS CLEAR FORWARD MESSAGE to A-GP A - GP SENDS CLEAR FORWARD REPORT to B - GP B-GP SENDS CF SIGNAL OVER TRUNK to A-LTG ( B-EX) B-GP SENDS CF ACK. REPORT TO A-GP A-GP RELEASES GS ( idles PORT A ,user chl., A-CREG.) A-GP SENDS RELESE MESG. , CALL CHARGE & CALL DATA TO CP CP STORES DATA SUPPLIED , idles PORT A , the user chl., A-CHR and DELINKS A - CHR & B - CHR B-GP ON RECEIPT OF SIG. “IDLE”FROM B-EXCH.

11. RELEASES GS, idles PORT B , B - CREG, User Chl. 12 B-GP SENDS RELEASE MESG. TO CP .13. CP idles PORT-B , B-CHR, user chl.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11 .12. 13. 14. 15. 16. 17.

BAC KWARD

R

E LE AS E

B-SUB GOES ON-HOOK B - SLMCP DETECTS & SENDS CLEAR BACK MESG. to B - DLUC B - DLUC SENDS CLEAR BACK MESSAGE to B - GP B- GP SENDS CLEAR BACK REPORT to A - GP A-GP SENDS CB SIGNAL OVER TRUNK to B-LTG ( A-EX) A - GP SENDS CF REPORT TO B - GP B - GP SENDS idle BD command to B - DLUC B - DLUC SENDS idle BD to B -SLMCP B - SLMCP SENDS idle BD ACK. to B - DLUC B-DLUC SENDS idle BD ACK. MESSAGE to B-GP B-GP RELEASES GS ( idle PORT B , B - CREG ,user chl. B-GP SENDS idle BD MESG. TO CP CP idles PORT- B , B - CHR & user chl. & delinks CHRs A-GP Receives CF SIGNAL OVER TRUNK From B-LTG (A-EXCH) ( A-SUB goes ON-HOOK or AFTER TIME-OUT A-GP releases GS, idles PORT - A , A - CREG , user chl. A-GP sends RELEASE MESG. To CP CP idles PORT - A , User chl. ,A - CHR.

TRANSIT CALL 1.

Requires only first 3 to 4 digits ( Only in case of R2MF )

2. 3.

A-GP detects SEIZURE ( seizes A-CREG , TS , PORT A ) and sends SEIZURE Message to CP A-GP sends SEIZURE ACK. Signal over Trunk to Orig-EX.

4.

CP Seizes ( PORT -A Seized , A-CHR )

5.

A-GP Receives digits & Sends DIGIT BLOCK (CPT) to CP

6.

CP Searches for idle PORT, Path in SN & Sends SEIZURE BT to B-GP

7. 8.

B-GP Seizes ( B-PORT , B-CREG , TS )

9. 10.

CP Informs A-GP ( B-LTG No. , PORT No. ) A-GP Performs COC , if +ve Sends SETUP COMPLETE Report to B-GP A-GP is connected to B-GP , A-GP asks Originating Exch. to Send from 1st digits ( Step Back Signal )