Configuring a T1 Port
Page 33-4

Configuring a T1 Port

The temod command configures a T1 port at the physical level and is generic to all such ports
regardless of the logical level service, such as circuit emulation, that controls them.
To configure a T1 port, enter the following command
temod <slot>/<port>
where <slot> is the slot number where the board is located, and <port> is the T1 port number
on the board that you want to modify. For example, to modify port number 2 on the board in
switch slot 5, enter
temod 5/2
A screen similar to the following displays:
T1 Port Configuration for slot 5, port 2
1) Circuit Identifier (30 chars max) : Alcatel T1 Circuit
2) Frame Format { ESF (2), SF (3), unframed (8) } : ESF
3) Line Build Out { short(1), long(2) } : short
30) Line Length in meters (0-200) : 30
4) Line Coding { B8ZS (2) , AMI (5) } : B8ZS
5) Facility Datalink { ANSI T1.403 (2), AT&T 54016 (4),
T1.403-AT&T (6), none (8) } : none
6) Facility Datalink Port Role { network (1), user (2) } : network
7) Transmit Clock Source { loopTiming (1),
localTiming (2) } : localTiming
8) Loopback Mode { none (1), payload (2), line (3),
inward (5) } : inward
9) Signalling { none (1), CAS (2), CCS (3) } : none
10) Trap Generation { enabled (1), disabled (2) } : disabled
11) Yellow Alarm Detection { enabled (1), disabled (2) } : enabled
Enter (option=value/save/cancel) :
1) Circuit Identifier
Enter a textual description of this T1 port, up to 30 characters. This text will be used in other
screen displays to identify this T1 port.
2) Frame Format
Specify the frame format to be used on this port. The choices are Extended SuperFrame
(ESF), SuperFrame or D4 (SF), or no special frame format (unframed). A T1 frame consists of
24 8-bit time slots and a 1-bit synchronization and control. Twelve (12) T1 frames can be
grouped into a SuperFrame, and 24 T1 frames can be grouped into an Extended SuperFrame.
Normally, you should configure a T1 port as ESF (the default) since a T1 port configured as
SuperFrame (SF) can produce false yellow alarms if a Layer 2 protocol like High-Level Data
Link Control (HDLC) is being used.
If you must set the port as SF, you can disable Yellow Alarm detection with the Yellow Alarm
Detection option, which is described on page 33-7.