Subject: Re: [TICTOC] bi-directional SyncE - Copper GBE

From: "STUART VENTERS" <[email-masked]>
Date: Tue, 24 Mar 2009 14:11:40 -0500

Ronen,

It looks like the words that ended up in 8264 to deal with this might require some reading between the lines
  to understand that you need to force the negotiation to setup the desired clock path.

For interoperability, it would have been nice if the words said to force it at the master, or slave , or both.

I think Yaakov just said to force it at the master?

Alternatively, you could make it provisionable if your hardware knows how to do it either way.

Here are the words in G.8264 related to this.

Rec. ITU-T G.8264/Y.1364 (10/2008) - Prepublished version

10.1 Synchronous Ethernet: General
Note: there may be sync Ethernet interfaces with reduced functionality in the sense that they might
provide sync Ethernet functionality in a single direction only (transmit or receive). Details are for
further study.

10.2 Operation modes
Synchronous operation mode

In the particular case of Ethernet interfaces for 1G copper as specified in IEEE 802.3, these
interfaces perform link auto negotiation to determine the master and slave clocks for the link. In the
case where these interfaces are used for Synchronous Ethernet, the resulting timing path must be
considered if frequency distribution based on Synchronous Ethernet is used. The clock master must
be consistent with the network synchronization plan.

Regards,

Stuart Venters
Adtran