Configuring a T1 Port
Page 33-6
5) Facility Datalink
Facility Datalink (FDL) gathers performance statistics every second and stores them in the 24-
hour local statistical database. It also sends local performance statistics to the remote T1 port
depending on the type of FDL chosen and the “role” of the FDL (specified in the next field).
In order to obtain far-end, or remote, performance statistics (viewed through the terts, tercs,
and teris commands), you must enable an FDL protocol.
Note
Facility Datalink requires a T1 port and the frame type
must be Extended SuperFrame.
You have the following choices:
ANSI T1.403 The FDL exchange recommended by ANSI. The FDL method sends Perfor-
mance Report Messages (PRMs) to the far-end port every second, processes
received PRMs, and stores them in a 24-hour far-end statistical database.
AT&T 54106 The operation of this FDL protocol depends on the Facility DataLink Port
Role setting (configured in the next field). The FDL protocol will either be
active (network) or passive (user) in its sending of PRMs.
T1.403-AT&T In this combination selection, the port supports both the ANSI (ANSI T1.403)
and AT&T Extended Superframe (AT&T 54106) protocols at the same time.
The port processes ANSI messages as described for the ANSI T1.403 option
and responds to AT&T request messages.
none The port does not use Facility Datalink.
6) Facility Datalink Port Role
Indicates the role of this port in relation to the remote port. This setting only affects configu-
rations where the Facility Datalink field is set to AT&T 54016. When set to network, far-end
historical statistics are updated by periodically sending 24-hour and 1-hour performance statis-
tics requests to the far-end port. When set to user, the FDL passively waits for messages from
the far-end port.
7) 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 PLLs) is used as the transmit clock.
The transmit clock source is related to the clocking mode used in circuit emulation services.
In synchronous clocking mode, both sides of the T1 connection will use a local clock source.
However, in SRTS and adaptive clocking, the T1 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
T1 port receiving the clock from the network should be configured as loop timing and the
other end of the link should be configured as local timing.