User guide

2-4 DL3800 DS1 Inverse Multiplexer User Guide—February 1999
2
interface. To allow for jitter and wander speciÞcations, the read address
counter will be positioned approximately three frames behind the write
address for the network last in time.
T1 Port Mismatch Detection
When the IMUX T1 circuits synchronize, they use the AT&T 54016 Facility
Data Link to communicate which ports (1-8) they are. Ports that are
mismatched (that is, not connected to a port with the same number)
identify themselves as mismatched and take themselves out of IMUX
service.
Mismatched ports taken out of service are identiÞed as mismatched by a
message in the ALARMS and STATUS MENU. No event is registered for
this status item in the Event History.
An IMUX T1 circuit is re-established as soon as the mismatched circuits are
disconnected and re-connected properly.
This feature is only enabled when the T1 network conÞguration speciÞes
FDL mode as ATT or ON.
Port number communication is done using a Digital Link proprietary
message in the 54016 FDL.
Figure 2-2 is a Functional Diagram of the DL3800 showing a unit
supporting four T1 lines.
Figure 2-2 DL3800 Functional Schematic
T1 Framer
T1 Framer
T1 Framer
T1 Framer
T1 Framer
T1 Framer
T1 Framer
T1 Framer
Buffer
Buffer
Buffer
Buffer
V.35 or HSSI DTE In t .
DS1 In t er .
DTE
T1
Networks
IMUX Fr amer
IMUX Fr amer
IMUX Fr amer
IMUX Fr amer
DS1 In t er .
DS1 In t er .
DS1 In t er .
DS1 In t er .
DS1 In t er .
DS1 In t er .
DS1 In t er .
IMUX
Framer