This is an interesting proposal.  I believe that some kind of multi-path scheme 
for timing packets has value.

In section 5.2.1 (Two-way MPPTP) it states:

Every clock periodically sends a set of N Announce messages, using
its N addresses as the source IP address.

In 1588, however, only the best master sends multicast Announce messages.  
Slaves never send Announce messages, and non-best masters do only if they set 
the Alternate Master Flag (see IEEE-1588-2008, sec. 17.4). However, masters can 
obtain slave addresses from received Delay Requests. Also, if masters used the 
Alternate Master Flag,  it would help prevent slaves which are not capable of 
mulit-path, from getting confused.

Alternatively this could be done without Alternative Masters, using the Unicast 
Discovery mechanism (IEEE-1588-2008, sec. 17.5) In this mechanism slaves must 
start with a list of master addresses.  The slaves then send unicast Announce 
message requests to the addresses, and subsequently receive unicast Announce 
messages.

//Doug Arnold
Symmetricom
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