Subject: Re: SONET MIB using for the SDH

From: Ken Chapman <[email-masked]>
Date: Fri, 26 Feb 1999 18:32:19 -0500

At 08:47 AM 2/26/99 -0800, C. M. Heard/VVNET, Inc. wrote:
>On Thu, 25 Feb 1999 [email-masked] wrote:
>> 
>> SDH has cross-connection function between VC12 and TU12. VC and TU one-to
>> one correspondence is correct if we don't need to use it.
>> For example, if we need protection then two TU12 correspond to single VC12.
>> First TU12 is working and connected to VC12. Second TU12 is allocated for
>> the same VC12 and not in use. But anyway the second TU12 should be ready to
>> work, so we need to monitor it by manager.
>> 
>> How can we use SONET-MIB to manage situation like this? It can be done more
>> simple if TU12 and VC12 are different objects.
>
>One suggestion that comes to mind is to model the "spare" TU12s via separate
>ifTable entries of ifType = 51(sonetVT), and instantiate the corresponding
>SONET-MIB sonetVT managed objects, but do NOT indicate (via the ifStackTable)
>that these "spares" are connected to any lower layer while they are not in
>use.  You will then need to add objects to your enterprise MIB to indicate
>which of the active ifTable entried of ifType = 51(sonetVT) that the "spare"
>object is backing up, and to manage the switchover.

Another possibility is to model the APS pair as an interface on top of the two
TUs and then put the VC over the APS interface.  You would then have 4
interfaces
(ifIndexes) and the stack would have two entries for the APS over the two
TUs and
one for the the VC over the APS.  This could be done using the ifType =
70(channel) 
for the APS interface, or if that has another meaning (asside: where are the 
ifType value meanings described in any detail???) in you implementation ask
the
IANA for an new value for APS interfaces or use ifType = 1(other).
You could use ifOperStatus = dormant(5) on the TU to indicate that it is
the spare.

	Ken
================================================
Ken Chapman                 Argon Networks, Inc.
tel: +1-978-486-0665 x146   25 Porter Road
fax: +1-978-486-9379        Littleton, MA  01460
mailto:[email-masked]   http://www.Argon.com
================================================