[manet-dlep-rg] DLEP Capabilities exchange

["Stan Ratliff (sratliff)" <[e-mail]>]

Gentlemen, 


Well, sigh…  I've been frankly trying to avoid this, but it's a subject I want to breach - if not for DLEP-05, then maybe for an 06. 

I've been thinking again about some exchange of capabilities. Not for a DLEP session startup, but to cover some specific use cases. The first one I'll throw out is this: 

Consider a deployment using OSPF, over satellite. That OSPF network is defined as a standard broadcast (Ethernet) segment, with a Designated Router (DR) and a Backup DR (BDR). In the satellite implementation I'm considering, it would be a good thing if the DR was co-located with the SatCom "Network Controller". 

So, I'm thinking about a capabilities exchange, where the modem (the satcom terminal) tells the router "I'm the NC". This would, in turn, cause the connected router to be "very willing" (whatever that means) to be the DR in an OSPF election (the next election that occurs on this link)… There would also have to be an "I'm NOT the NC anymore" message that flows from modem to router if/when that function is reassigned in the network. 

I'm sure there are other cases. Let's see if we can make a run at enumerating (and hopefully "generalizing") them.

Regards,
Stan