Wael
hello,
I just reviewed request 1220 (thanks for fixing the
missing attachment).
Request 1220 identifies a problem in the 10G-EPON MAC (ie.
Multipoint MAC Control does not correctly account for a second laser burst
transmitted in a single grant).
1.
Regarding the proposed remedy:
- The
revised figure 77-14 defines a variable "IdleCount". I would
note that the MPCP layer is not aware of the IDLEs per se (as they are inserted
by the PCS layer in the absence of data to transmit).
- Moreover the
definition of IdleCount states "this variable advances by
1 after every 8-bit times". To
estimate laser-off time correctly the variable also needs to take the rate
adaptation of the transmitting PCS into account. This would
mean that the advancement of the variable halts while (fecOffset[1:0]
= 0).
2. So
with gratitude to the submitter of the maintenance request, it appears that additional study is needed to
determine the best response to request
1220.
3. As well, I
would like to suggest that additional study be given to the requests 1221 and
1222 - which also deal with clause 77
issues.
Thanks and Regards,
Jeff
Mandin
PMC-Sierra