ADTRAN 1000R Series

Command Reference Guide Enable Mode Command Set

Technology Review

A network loopback loops data toward the network (away from the unit). A customer loopback loops da ta

toward the router. The router does not instigate customer-side loopbacks, on ly network loopbacks (re mote

or local). The reason for this is that the customer interface is internal to th e router. There is little use for

looping back router data on itself.

A transparent loopback is one in which the unit loops back one side (i.e., network) and also allows the

same incoming data to be passed through to the customer side. A non-transparent loopback is one which

loops back o ne sid e o f th e in terface (networ k) bu t send s idle co des to the other side (customer ). The AOS

defaults to non-transparent loopbacks. The reason for this is that sending test patterns into the IP stack

could cause unpredictable behavior. However, it is still possible for the network to send a transparent

loopback request. Such requests will be accepted.