sdh-sonet >> RDI Alarm

by Netbot » Mon, 22 Jun 2009 12:45:18 GMT

please tell me the source of the alarm if the alarms pop in the
following manner.


X1 and X2 are outside our domain and ABC and D are the SDH nodes, let
say RDI alarms popped-up on all SDH nodes from X1->A, A->B, B->C and C-

Is X1 is the direction if problem or X2?

sdh-sonet >> RDI Alarm

by Netbot » Mon, 22 Jun 2009 17:02:35 GMT

> ===========================================================>====
> ttp://www.van>
> ===================================================>============
> Always remember that you are unique...just like everyone else...

Yes all the RDI alarms were popped up at the same time and there was
no event took place at that time, what i understand from your reply is
that "problematic node is X2" nothing had been transmitted from X2
towards X1 so RDI alarm insertion taken place in the reverse
direction. is it?

sdh-sonet >> RDI Alarm

by hhelvooort » Tue, 23 Jun 2009 04:04:03 GMT

Hello Emma,

You replied:

The problematic node is NOT X2.

The problemaqtic node could be X1.
The signal that starts at A is sent to X1 and if this signal is
before it arrives at ist destination the destination termination
will detect a loss of siganl and consequently send an RDI back to A.

The same for signal send from B and C and D.

So either the connection betweenA and X1 is interrupted or the
at the left of X1 is interrupted.
I node X1 completely fails no RDI will be received by A, B, C and D.

Regards, Huub.

reply to hhelvooort with 2 'o's
Always remember that you are unique...just like everyone else...

sdh-sonet >> RDI Alarm

by Netbot » Tue, 23 Jun 2009 12:25:31 GMT

Thanks Huub

Tx of A is problematic towards X1 so in return it sending Path RDI
notification to all the nodes. If Tx and Rx at A is failed it will
raised LOS alarm and sending AIS to all other nodes. is it?

sdh-sonet >> RDI Alarm

by Huub van Helvoort » Sat, 27 Jun 2009 22:48:53 GMT

Hello Emma,

Yes, correct.

Regards, Huub.

reply to hhelvooort with 2 'o's
Always remember that you are unique...just like everyone else...

Similar Threads

1. Can RDI alarm initiates traffic switching??

2. RDI and E-RDI

Bonjour Huub,

Is it always appropriate to talk about RDI in the G1 byte. According
to your experience, today, are some new equipments still treat only
RDI instead of E-RDI?

Thanks for your opinion,
best regards,

3. RDI/ERDI/RFI indications

4. RDI-P on LOS

I have a question on SONET defect handling:

If an LOS is detected on a PTE, should it generate an RDI-P? In Figure
6-5 in GR-253,
I see that a PTE must send both RDI-L and RDI-P on detecting an LOS,
Why should we generate RDI-P in this case?


5. RFI & RDI

6. Syncom ADM - looking for details on non-standard treatment of RDI

I have received a tidbit of third-hand and translated information
regarding the Syncom ADM's treatment of path RDI:
"Symcom sends RDI in both directions (working path & protection path)"

The context here is a 2 fibre SNCP ring.

Yes, I have asked for more details but am not hopeful that it will be
forthcoming quickly.

Do any of you fine SDH experts recall anything about such a problem?

For bonus points, can somebody tell me what the history of Syncom is?
Especially with respect to ECI?

Thank you very much.
Keith Hanlan
Ottawa, Canada

7. UPSR/SNCP Handling of P-RDI

8. T1 alarms persistant timer


    We experience with certain switches some sort of bursts of alarms, frame
errors from the switch side that clear almost imediatly. I am using a
persistant timer of just 300 ms I am wondering if I need a lot longer
persistant timer before disconnecting the callers when an alarm is present.

    Would anyone know what would be a good value from experience?.