Re: Issues in mapping Ethernet signal to SONET
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
sides?
It would be appreciated if you could help me to understand your
proposal correctly.
Best Regards,
Osamu
At 3:46 PM -0700 00.4.13, Norival Figueira wrote:
http://grouper.ieee.org/groups/802/3/10G_study/email/msg02306.html
> A presentation of the PCS2 function (i.e.,SONET
> compatibility function):
> http://grouper.ieee.org/groups/802/3/ae/public/mar00/figueira_1_0300.pdf
> 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.