Specifications

Interface Protocols
Operating Characteristics
3-26 68P81095E55-E August 08, 2000
Dispatch Application Processor
The DAPs are the dispatch call managers/router(s) in the network. Because of the
switch functions of the DAP, it has several interface types (Figure 3-19). The DAPs
connection to:
• EBTS-iSC using Frame Relay - LAP-D on V.35. This is an indirect link
through the MPS. The speed is at least 256 kbps from the DAP to the MPS,
and is set by the MPS. The Tandem DAP uses High Speed Serial Interface
(HSSI) to interface to the APDs
• OMC using X.25 - LAP-B / V.35. This is a 19.2 kbps direct link. However, the
newer Tandem DAP (TDAP) interface to the OMC is Ethernet.
• ADC using asynchronous RS-232. The subscriber information connection is
either an Ethernet link or a modem dial-up at 9.6 kbps
Metro Packet Switch
The MPS performs the cross connect functions under DAP control. The MPS
connects to the EBTSs over transport facilities. Connections between the DACS and
the MPS are T1. The MPS has no OMC-R link. Control and routing from the DAP
is exchanged over T1/E1 links using Frame Relay (Figure 3-19).
Packet Duplicators
APDs use a High Speed Serial Interface (HSSI) to communicate with the Tandem
version of the DAP.
The Operations and Maintenance Link (OML) for the PDs is by Frame relay on a T1
to the MPS and then using X.25 on V.35 cabling to the DAP. The OML with the
Tandem version of the DAP and APD is Ethernet running X.25.
Figure 3-19 Dispatch Interface Paths
High
Speed
Serial
Interface
(HSSI)
T-DAP-APD
only
MPS
(packet routing )
DAC
To Transport
facilities
APD
(multi-packet
source)
DAP
(Services &
Authentication)
circuit
breakers
T. N. French
T1's
Frame Relay
T1
Frame Relay
OMC-R
V.35
X.25
OML
Ethernet
X.25
OML
T-DAP only
OML
logical on T1
RS-232 Dial-up
or
Ethernet
ADC
Provisioining
LAP-D
LAP-D