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Layer 3 Switching Software Feature and Configuration Guide
78-6235-04, Cisco IOS Release 12.0(10)W5(18)
Chapter 4 Configuring Interfaces
Configuring the POS OC-12c Uplink Interface (Catalyst 8540)
Configuring Framing
The default framing mode for the POS OC-12c uplink interface is SONET STS-12c. You can also
configure the interface for SDH STM-4, which is more widely used in Europe. To configure the framing
mode on the POS OC-12c uplink interface, perform the following steps, beginning in global
configuration mode:
Configuring SONET Overhead
You can set the SONET overhead bytes in the frame header to meet a specific standards requirement or
to ensure interoperability of the POS OC-12c uplink interface with another vendor's equipment. To
configure the SONET overhead, perform the following steps, beginning in global configuration mode:
Command Purpose
Step 1
Router(config)# interface pos
slot/subslot/interface
Router(config-if)#
Enters interface configuration mode and specifies the POS
interface to configure.
Step 2
Router(config-if)# pos framing
{sdh | sonet}
Configures the framing mode.
POS framing defaults to SONET. The following default values
are used for SONET.
• s1s0 default value is 0.
• J1 defaults set to host name, interface name, and IP address.
The following default values are used for SDH framing:
• s1s0 default value is 2.
• J1 is the path trace string. Its default setting is empty and is
not configurable.
Step 3
Router(config-if)# no shutdown Enables the interface with the previous configuration.
Command Purpose
Step 1
Router(config)# interface pos
slot/subslot/interface
Router(config-if)#
Enters interface configuration mode and specifies the POS
interface to configure.
Step 2
Router(config-if)# pos flag {c2
value | j0 value | sls0 value}
Configures the SONET overhead bytes. c2 is a path signal
identifier, j0 is the section trace byte, and sls0 is the bit s1 and s0
of the H1 payload pointer byte.
Step 3
Router(config-if)# no shutdown Enables the interface with the previous configuration.