Subject: [sfc] Mail regarding draft-aldrin-sfc-oam-framework

From: "Deepak Kumar (dekumar)" <[email-masked]>
Date: Tue, 11 Nov 2014 20:32:04 +0000

Hi,

In section 2. SFC Layering Model

We have Service Layer which can also be broken down in the layers as within a service Function chain we can have multiple SFPs due to one of the SFF changing the classifier.

In Section 3.1 we are mentioning Availability which I am not sure is right term as performance management has concept of Availability also as a SLA, as for customer finding loss is not that important SLA but important SLA is availability and unavailability of the flow over time as that's the SLA that can be sold.

To find faults in real time Alarm Indication Signal technique or notification should also be considered, eg:- within a service function chain, one of the SFF/SF is restarted and this belong to multiple SFC chain.

In section 3.1.2 – This should be extended to say that protocol should be able to provide the SLAs instead of delay, and loss calculation. Just loss calculation is not enough to determine availability of circuit.

In section 4.1

We should also add verify packet re-ordering and corruption in unidrirectional connection.
Also we should say "Proactively and on-demand" test alternate or protected paths to ensure reliability of network configuration.

On Section 4.4 same Performance has to be extended.
Even for Performance we should have both proactive and on-demain support from the protocool to be developer later.

Most of the time Performance Measurement fails because OAM packet doesn't take the same path as data path and also where the timestamping or delay is measured. As "O" bit is in the header protocol has to be defined such that "o" bit is not checked in middle of network.

Framework should atleast talk about Measurement Point.

Thanks,
Deepak