Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index


Hi Dave,

Could you help me to understand how WAN-PHY and ELTE would react on 
SONET AIS (Alarm Indicaton Signal)?

When we have cable cut in SONET infrastructure, the SONET side of 
the ELTE will receive either Line-AIS or Path-AIS.

  Line-AIS: all '1' in Line OH and SPE payload.
            generated by the regenerator who detect upstream cable cut.
            detected by the last 3 bits in K2 (at least 3 consecutive '111')
  Path-AIS: all '1' in AU pointer and SPE payload.
            generated by LTE who detect upstream cable cut.
            detected by the all '1' in H1&H2 at least 3 consecutive frames.

Thank you,

At 5:13 PM -0400 00.6.1, David Martin wrote:
> Gary, Osamu,
> Regarding the need for B2/M1. My thinking behind proposing B1 & B3/G1 
> only is that B1 is sufficient for fault isolation, and B3/G1 can serve 
> adequately for performance monitoring in the typical BER operating 
> range (a carrier can tap in with Intermediate Path Performance 
> Monitoring - IPPM).
> Regarding the need for K1-2. I was thinking that protection switching 
> in the LAN is not a traditional feature. In the WAN, optical layer 
> protection could be used.
> Roy has suggested using J1 Path Trace. I can see value in that. 
> But I believe if we add more OH beyond the WIS proposal (i.e. B1, 
> B3/G1, J0), save J1, we'll be crossing the line from compatible 
> to compliant & adding unnecessary cost.
> ...Dave

NTT Network Innovation Laboratories
TEL +81-468-59-3263  FAX +81-468-55-1282