Re: (corrected) Re: [EFM] RE: OAM Transport Proposal
At 09:51 AM 4/23/2002 -0500, Roy Bynum wrote:
>If I understand you correctly, given that there will always be additional
>latency translating the MDIO/MDC frames into preamble information, and
>then send the preamble, even without a standard frame, it will not provide
>any advantage in greater responsiveness than OAMiF. If that is the case,
>then there is no advantage to OAMiP under any circumstances. If that is
>the case, why include it even as optional?
First, Preamble handler is located in RS layer ( RS layer is strictly a
part of PHY )
which has the high-speed control interface ( common to MAC and above ).
So the speed is not the issue. Refer the preamble proposals presented in
last several meetings.
The second, the OAMiF will be mostly like implemented by SW/FW
( that's the main reason why people want to use it ? )
the resulting latency would be unpredictable,
while OAMiP detect indication will be handle by HW with predictable latency.
The third, and PHY fault indication / protection by MAC control layer is
something like SONET protection handled by IP packets
which engineers never have used.
>At 06:59 AM 4/23/2002 -0700, Booth, Bradley wrote:
>>A management frame I described is that defined in Clause 22 as a MDIO/MDC
>>communication. If the preamble is filtered by the PHY, then there has to be
>>some way to pass this preamble OAM information to the management entity. In
>>802.3, this is done via MDIO/MDC (or management frames). A management frame
>>takes over 25 us to be passed across the MDIO/MDC interface. Unless the
>>intention is to have the PHY handle all OAM in preamble without management
>>entity intervention, then the response to the OAM in preamble will be
>>hampered by the MDIO/MDC interface.
>>Sent from my Blackberry...