OAM Alarms and Loopbacks
62 Avidia System Configuration and Management User Manual
Avidia Channel Card to Modem Segment Loopback
The ADSL modems (Megabit Modem 700F, 60 0F , and 500L software versions 2.6 and later)
support F5 flow OAM loopbacks. (Megabit Modem 700F, 600F, and 500L software version 2.7
and earlier do not support F4 flow loopback for VPCs.) Since anxDSL modem terminates ATM
service, the modem automatically loops back any OAM loopback cells it receives on any
configured PVC. The modem does not require additional configuration or addressing (such as
an OAM Location ID address) to respond to OAM loopback testcells.
The figure below shows a simple Avidia to modem OAM segment loopback. The segment test
is run between an ADSL channel card (AV541) and a Megabit Modem 700F, 600F, or500L.
The modem must have at least one user session (PVC) defined and active. Dependingon the
model of the modem, the session could be either PPP (Megabit Modem 700F, 600F, or 500L)
or bridging/routing (Megabit Modem 700F only).
In the loopback example shown above, the OAM test cells originate and terminate at the source
Avidia channel card (point B). The modem (point A), which is the target or destination device,
does not generate any OAM cells. The modem loops back OAM test cells to the originating or
source device (point B).
You can configure OAM loopbacks to run on each separately defined and active PVC for
theMegabit Modem 700F and 600F since these modems support multiple simultaneously
activeP VCs. The M eg abit Modem 700F supports up to 32 simultaneously active PVCs.
TheMegabit Modem 600F supports up to three simultaneously active PVCs.
Point B - channelcard
ADSL Loop
OAM Segment Loopback
Avidia System
Megabit Modem
MEGABITMODEM
Point A