Use Loopback Testing for Channelized OC-12 Interfaces

This chapter describes using loopback testing to isolate Channelized OC-12 and Channelized OC-12 IQ interface problems. (See Table 58.) The procedure for both types of Channelized OC-12 interfaces is the same. The naming convention for the Channelized OC-12 IQ interface varies depending on the type of interface. For a list of interface types associated with the Channelized OC-12 IQ interface, see Channelized Intelligent Queuing Interface Naming.

Table 58: Checklist for Using Loopback Testing for Channelized OC-12 and Channelized OC-12 IQ Interfaces

Channelized OC-12 or Channelized OC-12 IQ Loopback Testing Tasks	Command or Action
Diagnose a Suspected Hardware Problem with a Channelized OC-12 or Channelized OC-12 IQ Interface
Create a Loopback
Create a Physical Loopback	Connect the TX port to the RX port.
Configure a Local Loopback	[edit interfaces t3-fpc/pic/port:channel t3 options] set loopback local show commit
Verify That the Interface Is Up	show interfaces t3-fpc/pic/port:channel extensive
Clear Interface Statistics	clear interfaces statistics t3-fpc/pic/port:channel
Force the Link Layer to Stay Up
Configure Encapsulation to Cisco-HDLC	[edit interfaces t3-fpc/pic/port:channel] set encapsulation cisco-hdlc show commit
Configure No-Keepalives	[edit interfaces t3-fpc/pic/port:channel] set no-keepalives show commit
Verify the Status of the Logical Interface	show interfaces t3-fpc/pic/port:channel
Ping the Channelized Interface	ping interface t3-fpc/pic/port:channel local-IP-address bypass-routing count 1000 rapid
Check for Interface Error Statistics	show interfaces t3-fpc/pic/port:channel extensive
Diagnose a Suspected Circuit Problem
Loop the Entire T3 Interface towards the Network	[edit interfaces t3-fpc/pic/port:channel t3-options] set loopback remote show commit
Create a Loop to the Router from Various Points in the Network	Perform Steps 2 through 8 from Diagnose a Suspected Hardware Problem with a Channelized OC-12 or Channelized OC-12 IQ Interface.