Adtran 624 User Manual

Page of 264
Section 4  User Interface Guide
Total Access 600 Series System Manual
 90
© 2004 ADTRAN, Inc.
61200624L1-1B
L2 P
ROTOCOL
 (TDM F
IRMWARE
) – T1 I
NTERFACE
Configure the L2 Protocol parameters and view the status of the Network T1 interface using items from 
this menu.
L2 P
ROTOCOL
 (TDM – T1) > P
ROTOCOL
Configure the L2 protocol mode. Choices are 
PPP
FRE
HDLC
, and 
A
UTO
 (def). Selecting 
PPP
 configures 
the interface for Point-to-Point Protocol signaling on Layer 2. Selecting 
FRE
 configures the interface for 
frame relay signaling on Layer 2. Selecting 
HDLC
 configures the interface for generic High-Level Data 
Link Control signaling on Layer 2. Selecting 
A
UTO
 enables the Auto-config feature. 
L2 P
ROTOCOL
 (TDM – T1) > P
ROTOCOL
 > PPP
Point-to-Point Protocol (PPP) is an 8-bit serial protocol which allows a PC to connect as a TCP/IP host to a 
network through an asynchronous port. PPP is used for connection from a PC to an Internet Service 
Provider (ISP) for Internet access. PPP works over synchronous and asynchronous circuits. 
Router-to-router and host-to-network connections can be made via PPP. PPP includes error detections 
which Serial Line Internet Protocol (SLIP) and other protocols do not.
L2 P
ROTOCOL
 (TDM – T1) > P
ROTOCOL
 > FRE
Frame Relay is a switched data link layer protocol that handles multiple virtual circuits using High-Level 
Data Link Control (HDLC) encapsulation. Frame Relay uses statistical multiplexing as opposed to 
time-division-multiplexing to multiplex many logical connections over a single physical link. It contains a 
cyclical redundancy check (CRC) for detecting bad data, but leaves the error correction algorithms to be 
performed by higher protocol layers. Similarly, Frame Relay uses simple congestion notification. This 
notification in turn can alert higher-layer protocols to exercise flow control. These characteristics allow 
Frame Relay to provide a more flexible and efficient use of bandwidth.
L2 P
ROTOCOL
 (TDM – T1) > P
ROTOCOL
 > HDLC
HDLC (High-level Data Link Control) is a group of protocols or rules for transmitting data between two 
network points (point-to-point transmission). HDLC provides a low overhead system for transmitting data 
over Layer 2. IP packets are encapsulated into frames with an HDLC start and end flag. Generic HDLC 
protocol should be used when connecting with remote equipment using proprietary HDLC encapsulation 
methods. 
L2 P
ROTOCOL
 (TDM – T1) > P
ROTOCOL
 > A
UTO
Setting the 
L2 
PROTOCOL
 to 
A
UTO
 allows the unit to automatically detect the 
L2 
PROTOCOL
 from the 
network.
The 
L2 
PROTOCOL
 must be set to 
A
UTO
 in order to use the Auto-config feature.