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Re: Issues in mapping Ethernet signal to SONET


Please refer to the presentation indicated below (in your email).
It further explains our proposal for H3 usage and single pointer
processor at the receive path of the WAN PHY.

Best regards,

Norival Figueira, Ph.D.
Nortel Networks
4401 Great America Parkway
Santa Clara, CA 95054
Tel: 408-495-3674

At 12:19 PM 4/14/00 +0900, Osamu ISHIDA wrote:
>Dear Figueira,
>Thanks for your clarification, but I feel I have some confusion 
>about pointer manipulation in your WAN-PHY with SONET-framing, 
>especially how to treat the pointer H3 bytes.
>My question is whether your WAN-PHY and/or ELTE requires or does 
>not require the CLK-frequency justification mechanism by the H3 
>bytes.  And are there any difference between transmiter/receiver 
>It would be appreciated if you could help me to understand your 
>proposal correctly.
>Best Regards,
>At 3:46 PM -0700 00.4.13, Norival Figueira wrote:
>> A presentation of the PCS2 function (i.e.,SONET
>> compatibility function): 
>> Another function that is required at the receiver side is a 
>> pointer processor, i.e., only one pointer processor. This is not
>> a complicated function. The PCS2 frame has a pointer on
>> the H1/H2 octets that can be incremented, decremented, or set to
>> a new value.  The receiver PHY uses the pointer value to locate
>> the first octet of the SPE (this is SONET terminology for
>> Synchronous Payload Envelope). At the transmitter side, the PCS2
>> always transmits PCS2 frames with a same fixed pointer value.
>> Note that a pointer processor is required because the pointer
>> value may be changed by a SONET transport network. The pointer
>> may change when the receiver side of an LTE has a slightly different
>> clock from the one on the transmitter side. This is exactly the
>> mechanism an ELTE will use between the +-100ppm clock of the
>> 10GE WAN PHY and the SONET network clock.