Table of Contents
Advertisement
Ethernet LAN
Figure 1. Cisco router with serial interface, configured as PPP Half Bridge.
S2-4
Off
On
Line Framing Options:
D4/Superframe: The D4 framing format, as specified in AT&T
TR62411 is the standard in which twelve frames make up a
superframe. All signaling and synchronization are done in-
band.
Extended Superframe (ESF): Extended Superframe, as speci-
fied in AT&T TR 54016, consists of twenty-four (24) T1
frames. The framing bits are now used for framing, CRC and
the Facility Data Link (FDL). The FDL allows maintenance
messages and information to be passed between the 2720
and the Central Office.
Line Coding Options:
Alternate Mark Inversion (AMI): This mode does not inherently
account for ones density. To meet this requirement, each time
slot can be reduced to 56 kbps and the Least Significant Bit
(LSB) of each time slot set to one.
!
no ip routing
!
interface Ethernet0
ip address 1.1.1.1 255.255.255.0
bridge-group 1
!
interface Serial0
ip address 1.1.1.1 255.255.255.0
encapsulation PPP
bridge-group 1
!
interface Serial1
ip address 2.2.2.2 255.255.255.0
bridge-group 1
!
bridge 1 protocol ieee
!
Figure 2. Transparent bridging between two routers over a serial interface.
Patton
2720
Bridge
PEC Device w/ Serial I/F
Line Framing & Coding
ESF/B8ZS
D4/AMI
Bipolar 8 Zero
Router A
S1
Router B
S1
e0
LAN
LAN
8
Router
Serial Interface
S0
e0
Using Bridge-Groups, multi-
LAN
ple remote LANs can be
bridged over the wide-area.
S0
e1
Serial Interface
2720/I
T1/FT1 Link
LAN
LAN
2720/I
T1/FT1 Link
Advertisement
Table of Contents
