Callsetup Local Present

A-Sub

A-SLMCP

A-DLUC

A-GP

CP

SGC

B-GP

A-Sub (1)

A-SLMCP Off hook

(2)

A-GP

A-DLUC Seizing

(3)

Seizure AD

(a) Channel idle

(4) (5)

(7)

Seizure AD

TOG

Dial tone (12)

Set up

CR

(9)

SLMCP Check (11)

1st digit

SLMCP disconnect (16)

TOG (10)

15

digit digit digit

(18) Seizure Command

24

(6)

(b) Port A Seized

(8)

IT 13

(14)

B-GP

CP

SGC

DT 21 20 switched off (17) Digit (c) Port A Receiving 19 Block 22 Seizure BD

23

© Port B from Port A

A-Sub

A-SLMCP

A-GP

A-DLUC

B-GP

CP SGC 21

(14)

RBT

20

(c) Port A Receiving

22 Seizure Command

23 24

Seizure BD

© Port B from Port A

CR disconnect, store SETUP Zoning and COC start SETUP

(25)

COMPLETE

RBT

28 30

Ring 29

26 Address complete

27

TOG CR RBT

A-Sub

A-SLMCP

A-DLUC

A-GP

CP SGC

RBT

B-Sub

Ringing tone end (32)

30

Meter pulse (34)

Answer 31

Answer (33)

B-GP

A-Sub

A-SLMCP

A-DLUC

A-GP

CP

Conversation (35)

SN

B-GP

A-Sub

A-SLMCP

A-DLUC

A-GP

CP

Conversation (35)

SN

Clear back (36) Called Sub On hook

B-GP

A-Sub

A-SLMCP

A-DLUC

A-GP

CP

Conversation (35)

SN

Clear back (36) Called Sub On hook

Clear back (37)

B-GP

A-Sub

A-SLMCP

A-DLUC

A-GP

CP

Busy tone (38) TOG

SN

Clear back (36) Called Sub On hook

Clear back (37)

B-GP

A-Sub

A-SLMCP

A-DLUC

A-GP

CP

Busy tone (38) TOG Clear Forward (39)

SN Clear (40)

Clear back (36) Called Sub On hook

Clear back (37)

B-GP

A-Sub

A-SLMCP

A-DLUC

A-GP

TOG Clear Forward (39)

CP

SN Clear (40)

Clear back (36) Called Sub On hook

Clear back (37)

Clear Acknowledgement (41)

B-GP

A-Sub

A-SLMCP

A/BDLUC

A-GP

TOG Clear Forward (39)

CP

SN Clear (40)

Clear back (35) Called Sub Clear back (36)

On hook

Idle A (42)

Clear Acknowledgement (41) Release C (43)

B-GP

A-Sub

A-SLMCP

A-DLUC

A-GP

CP

B-GP

SN

TOG Clear Forward (39)

Clear (40)

Clear back (36) Called Sub Clear back (37)

On hook

Idle A (42)

Clear Acknowledgement (41) Release C (43)

Idle B (44) Idle B Acknowledgement (45)

A-Sub

A-SLMCP

A-DLUC

A-GP

CP

B-GP

SN

TOG Clear Forward (38)

Clear (39) Release C (45)

Clear back (35) Called Sub Clear back (36)

On hook

Idle A (41)

Clear Acknowledgement (40) Release C (42)

Idle B (43) Idle B Acknowledgement (44)

A-DLUC

A-GP

CP

ACREG

Off hook

Seizure AD

B-GP

B-DLUC

B-CHR

Dial tone 1st digit

ACREG

Digit block

CPB

nth digit B-CHR

Set up SN

C a l l i n g S u b s c r i b e r

C a l l e d

Seizure B-CHR

BD

BCREG

A-CHR

Set up Ring back

(COC)

CPB

x Ringback

Complete

Ringing Off-hook

Answer

Meter pulses

ACREG

On-hook Idle

AS U B

ACREG x

Clear forward Release A

Busy tone

BS U B

B-CHR A-CHR

x B-CHR

x 1)

Seized Port A receiving Port A to port B or port B from port A

x

Release B BCREG x

S u b s c r i b e r

On-hook

Release/idle

Wait for release 1) Change meter

Fig. 2.2 : Sequence of data memory seizures for an internal call



INTERNAL A-Sub

A-SLMCP

A-DLUC

CALL CP

A-GP

SGC



B-GP