Zhone Technologies IMACS Network Device - Manual (Page 14)

Zhone Technologies, Inc. IMACS Product Book, Version 4
March 2001 Page 10
As shown in Figure 4 the IMACS supports multiple methods of communicating SNMP messages and Telnet
terminal sessions between an end node and the network management station. The addition of PPP support allows
the IMACS to connect to routers or terminal servers to establish a connectivity path to the network management
station. The utilization of PPP is similar to that of SLIP.
T1/E1
PPP
Frame
Relay
PSTN
PBX
Router
Figure 4 - SNMP Messages and Telnet Sessions on IMACS
IMACS Management Using FDL/SA4
Another method of transporting IP datagrams is via the Facility Data Link (FDL) on a T1 link using the Extended
Super Frame (ESF) format. The FDL channel is a 4 Kbps channel available on the DS1 frame in the ESF overhead.
The SA4 bits in the frame alignment word of the E1 constitute the equivalent for E1. This method requires that a
DACS II is used in the central office, and is provisioned to extract the FDL / SA4 stream from the T1 /E1 and map it
into a DS0 channel. DS0 channels from each remote node are then transported to an IMACS equipped with a B7R
or MCC card so that IP datagrams can be extracted.
The use of the 4 Kbps FDL to carry management information across the network is illustrated in Figure 6. The
remote IMACS at the top of the figure are terminated in a DACS II. The remote IMACS transport the TCP/IP
management information across the FDL. The DACS II transforms the FDL channel into a DS0 channel using its
proprietary B7R encoding scheme. These DS0s, carrying management information are combined with other DS0s
carrying user information and arrive at the IMACS as shown in the bottom of the figure.