Opened 6 years ago

Last modified 6 years ago

#15 new defect

Whether the control plane operates on SFC IDs, SFP IDs, etc.

Reported by: mohamed.boucadair@… Owned by: draft-ietf-sfc-control-plane@…
Priority: major Milestone:
Component: control-plane Version:
Severity: - Keywords:
Cc:

Description

The draft includes this note:

[[Note: The question of whether the data plane operates just in
terms of SFP IDs or needs SFC IDs, as described in this version
of the draft, is still under discussion among the authors.]]

The current version of the draft is more generic as it does not preclude manipulating service chains based on an identifier of the chain. Also, it does not assume that the SFP indirection level is mandatory (SFP IDs).

Note the current version accommodates various deployment contexts: e.g., rely solely on a chain ID, rely on a chain ID and a SFP, supply a strict path, supply a loose path, etc. The purpose is to not dictate deployment choices on how forwarding is actually achieved within an SFC-enabled domain.

An identifier of the chain is the minimum information that is needed, but other information may be supplied as well.

Feedback from the WG about which information to supply is needed.

FWIW, there is a ticket issue for this issue for the nsh spec.

Change History (1)

comment:1 Changed 6 years ago by mohamed.boucadair@…

The following changes are made in -01:

OLD:

o SFC Forwarding Policy Table: this table reflects the SFC-specific

traffic forwarding policy enforced by SFF components for every
relevant incoming packet that is associated to one of the existing
SFCs.

[[Note: The question of whether the data plane operates just in
terms of SFP IDs or needs SFC IDs, as described in this version
of the draft, is still under discussion among the authors.]]

NEW:

o SFP Forwarding Policy Table: this table reflects the SFP-specific

traffic forwarding policy enforced by SFF components for every
relevant incoming packet that is associated to one of the existing
SFCs. The SFP Identifier (SFP-id) is used as a lookup key to
determine forwarding action regardless of whether the SFC is fully
constrained, partially constrained, or not constrained at all.
Additional information such as a flow identifier and/or other
characteristics (e.g., the 5-tuple transport coordinates of the
original packet) may be used for lookup purposes. The set of
information to use for lookup purposes may be instructed by the
control plane.

  • Add this NEW text to Section 1.3:

NEW:

As a reminder, a Service Function Path (SFP) designates a subset of
the collection designated by the SFC. For some SFPs, in some
deployments, that will be a set of 1. For other SFPs (in the same or
other deployments) it may be a larger set. For some SFPs in some
deployments the SFP may designate the same set of choices as the SFC.
This document accommodates all those deployments.

  • Others minor edits.
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