Avaya 03-300430 User Manual

●

Check the diagnostic information for the timer number that has expired. See 

●

Check that the protocols at each end of the interface match (for example, both sides are 
AT&T Custom or both sides are NI-2). 

- If the ends of the interface are running different protocols, they might be running with 

different values for their Layer 3 timers. 

- If the protocols at each end of the interface match, the Communication Manager timer 

might have expired because:

1

T302

4s

SETUP_ACK messages (overlap receiving mode)

2

T303_1

4s

SETUP message 1st timer expiration

3

T303_2

4s

SETUP message 2nd timer expiration

4

T305

4/30s

DISCONNECT message

5

T308_1

4s

RELEASE message 1st expiration

6

T308_2

4s

RELEASE message 2nd expiration

7

T310

10s

CALL_PROCEEDING message

8

T313

4s

CONNECT message

9

T313_2

4s

“no longer used”

10

T316

120s

RESTART message

11

TL3

30s

Layer 3 timer expired (d-channel dropped)

12

T309

90s

d-channel reestablishment expiration stable calls are 

dropped 

13

T_WRN

h

FACILITY message (waiting for ACK or REJ)

14

T321

120s

SERVICE message (waiting for ACK)

15

TSM

h

retransmission of SERVICE on d-channel switchover

16

TM100

h

ISDN-BRI maintenance (MIM timer)