Lucent Technologies Definity Enterprise Communication Server 8.2 User Manual

Issue 1

April 2000

Features and technical reference 

1320

DS1 Trunk Service 

Common-channel signaling (CCS) is an industry-standard technique where any 
one of a group of channels carries the signals for the other channels. Lucent 
Technologies uses the 24th channel of a group for signaling. This signaling 
technique differs from 24-channel signaling. When the system is configured for 
Facility-Associated Signaling, 24-channel signaling uses the 24th channel in a 
DS1 facility to carry signals. This technique also is called clear channel, 
out-of-band, or alternate voice data (AVD) signaling.

TN464C, 
D, E, F

3

, 

and 
TN2464

1-24

1-23 (24th 
is D-chan)

1-31 (16th 
is D-chan)

1-24

1-31

1-30

1.544

4

2.048

1.544

4

2.048

2.048

alaw/mulaw

alaw/mulaw

alaw/mulaw

robbed-bit

isdn-pri

4

isdn-ext

4

CAS

CO/DID/Tie

ISDN

ISDN

ISDN

CO/DID/Tie

TN2242

1-30

1-30

7

2.048

2.048

alaw/mulaw

alaw/mulaw

CAS

isdn-pri

Tie

ISDN

1.

CO is any of the following trunk types: CO, FX, WATS.
Tie is any of the following trunk types: access, tie, tandem, RLT, APLT.

2.

Common-channel DS1 circuit packs used in CO trunk groups must have a trunk type of auto.

3.

Integrated CSU functionality is available only with the TN767D and TN464E or later-suffix DS1
circuit packs. Enhanced ICSU functionality is available only with TN767E, TN464F, and
later-suffix DS1 circuit packs.

4.

Mixed-mode signaling is allowed. This means that if the signaling mode is isdn-ext or isdn-pri, a
port from that circuit pack may be used in any trunk group that allows robbed-bit signaling.

5.

The TN464B’s companding is based upon the system companding that you administer.

6.

ISDN-PRI calls are not guaranteed to work for the TN464B if the system’s companding is set to
mu-law.

7.

The administered D-channel on the DS1 screen for ISDN-PRI cannot be a trunk group member.