Subject: [sfc] more questions to draft-ietf-sfc-nsf-01: what is the "Service Policy Selection"?

From: Linda Dunbar <[email-masked]>
Date: Wed, 18 Nov 2015 21:54:04 +0000

Paul and Uri,

A few more questions for draft-ietf-sfc-nsf-01:

-        What does "Location" mean in the Service Path Header definition?

-        Section 4 (NSH Actions) Bullet 4  has "Service Policy Selection" described as  "Service Function instances derive policy selection" . Then, I interpret it as for selecting which instantiation for the SF. But then it goes on to describe "Deny", "permit", seems to describe the internal policy for the SF . Internal policies to SF is much more than "deny" or "permit".  You have WAN Optimization SF, the Caching SF, the LB SFs, etc. It is beyond the scope of SFC to define policies to SFs.

-        Are the NH (Next Hop? ) in Figure 9~12 carried by NSH?  Or are they installed by out-of-band control messages?

-        Figure 8 shows that SFF can remove NSH but not Insert. Is it intended? If yes, why SFF only removes NSH but not insert?

Thanks, Linda