Alcatel Carrier Internetworking Solutions Omni Switch/Router - Manual (Page 998)

Configuring an E1 Port
Page 33-10
6) Transmit Clock Source
The source of the transmit clock. Loop timing means the receive clock (recovered from
receive data) is used as the transmit clock. Local timing indicates the local clock source
(generated from
PLL s) is used as the transmit clock.
The transmit clock source is related to the clocking mode used in circuit emulation services.
In synchronous clock mode, both sides of the
E1 connection will use a local clock source.
However, in SRTS and adaptive clocking, the E1 port receives the clock on one end (loop
timing) and regenerates the clock locally (local timing) on the other end. In such a case, the
E1 port receiving the clock from the network should be configured to loop timing and the
other end of the link should be configured to local timing .
7) Loopback Mode
The loopback configuration for this port. Loopback configurations describe the relation
between the device attached to an
E1 port and the framing functionality within the E1 port.
Framing functionality assembles E1 frames into multiframes, depending on how the port is
configured. Possible values are as follows:
none The port is not in a loopback state. This is the typical live network state for an
E1 port.
payload The received signal at this E1 port is looped out of the port after passing
through the port’s framing functionality. This state should only be used for
debugging purposes.
line The received signal at this E1 port does not go through the port’s framing
functionality, and is looped straight back out the port. This state should only
be used for debugging purposes.
inward The transmitted signal from the inwawrd side of this port is looped back inter-
nally. The signal passes through the E1 framing functionality before looping
back. This state should only be used for debugging purposes.
8) Signalling
The type of signaling used on this port. Only the none and CAS (Channel Associated Signal-
ling) options are applicable to a circuit emulation service port. The CCS (Common Signal
Channeling) option is used with external ISDN ports. If you select the CAS option, then you
are enabling Channel Associated Signalling, which is used with E1 multiframes. In Channel
Associated Signaling, timeslot 16 in frame 0 of the multiframe is used for multiframe synchro-
nization and control. Timeslot 16 of frames 1 through 15 are used to carry A, B, C, and D
signaling bits.
9) Trap Generation
Enables all of the SNMP -based traps related to circuit emulation service ports.