Subject: RE: [ANCP] Access-Node Partitioning

From: "Derek Harkness" <[email-masked]>
Date: Fri, 1 Sep 2006 10:40:21 +0100

Apoloigies for late response but I was off buying some wine for a while
there...............
 
In summary I know of multiple service provider demands for both hard
partitioning and redundancy.
I have yet to come across service provider demands for functional
partitioning.
 
Therefore I would prioritise them accordingly.
 
Customer scenarios for hard partitioning I have been made aware of
include:
 
(i) Residential/business split ( services often provided by different IP
edges belonging to different organisations within a provider )
(ii) Capacity planning ( i.e. a large AN which is mapped to a
controller/NAS which has reached it's capacity and therefore further
ports need to be turned up on another node ) 
(iii) Wholesale scenarios ( a provider sells a "viirtual AN" to a retail
provider ).
 
Redundancy is also a scenario service providers are very interested in.
 
Note that without wishing to get into that single edge / multi edge /
holy grail thing, if you solve the redundancy problem then you may also
be able to use this solution for a multi edge scenario ( your "internet"
and your "karaoke on demand" IP edges appear to be active/active
redundant, if that makes sense. )
 
I'm not sure functional partitioning solves multi edge ( maybe both
edges want to know the line BW ? ) and if I have a node which is
informed of the BW then it is probably providing a service across that
line and will want to verify via OAM if it's working. 
 
Maybe for line config I could see functional partitioning being useful -
with ANs having some kind of line config relationship with a "master
controller" but I think we are looking at corner cases here and getting
away from the main focus.
 
    Cheers,
 
        Derek.

 
+=============================+
Derek Harkness
Systems Engineer
Juniper Networks 
Nymphenburger Strasse 13-15
80335 Munich
Germany
Tel: +49 89 5529 4916
Mobile: +49 172 843 6621
Email: [email-masked]
+=============================+ 

________________________________

From: Sanjay Wadhwa 
Sent: 14 August 2006 16:35
To: Wojciech Dec (wdec); [email-masked]
Subject: RE: [ANCP] Access-Node Partitioning

IMHO, it will help to initially target "hard partitioning" and
controller redundancy.  The former is useful for instance in scenarios
where we would like to terminate residential and business DSL lines on
different IP edge nodes. 
Graceful restart on a single controller helps with resiliency. However
controller redundancy eliminates any single point of failure and is
explicitly listed in the scope of ANCP charter.
Once we are done with the work items in the initial charter we can
consider visiting "functional partitioning" (which is more relevant to
multi-edge architectures).
 
Regards
-Sanjay

	-----Original Message-----
	From: Wojciech Dec (wdec) [mailto:[email-masked]]
	Sent: Friday, August 11, 2006 7:56 AM
	To: [email-masked]
	Subject: [ANCP] Access-Node Partitioning

	Dear All, 

	During our IETF 66 ANCP meeting we briefly discussed the issue
of access-node partitioning and I took the action to attempt to commence
a discussion on what is actually required. The outcome of this would go
into the protocol requirements framework.

	Brief background. 
	The GSMP protocol (citing RFC3292 here ) allows for a mode of
operation whereby an access-node may be controlled by more than one
controller by using the technique of partitioning. In effect the
"physical" access-node can be partitioned into several virtual
access-nodes that are referred to as partitions. The partitions of a
physical access-node are isolated from each other by the implementation
and the controller assumes that the resources allocated to a partition
are at all times available to that partition. No controller redundancy
mechanisms are described.

	In other words, as applied to our ANCP use, the GSMP base
protocol allows for what may term a 1-1 control relationship between a
particular access-ports in one partition and a controller, with other
access-ports in other partitions having the same 1-1 relationship with
their controller. For the sake of the discussion, I'll call this
partitioning method "hard partitioning"

	Taking the partitioning concept above a step further, it is
possible to imagine what one may term as "functional partitioning"
scheme. In such a scheme, specific functions and/or data elements of a
particular access-port would have a 1-1 relationship with a controller
uniquely allowed to modify these functions or access data elements. 

	In terms of the ANCP use-cases, this could translate to a set-up
whereby for a single access-port, say the access-port's modem train rate
information would communicated to one controller (let's call it
controller X), while the OAM function, or configuration parameters would
be communicated with another controller (let's call it Y). 

	More elaborate combinations of such a scheme could also be
possible, eg having the modem train rate be communicated to both X and
Y, while retaining the OAM function's control only on controller Y.

	Given all of the above several questions appear to be
appropriate for a start: 
	- Is there interest in enabling ANCP with "hard partitioning"? 
	- In case of "hard partitioning", is it expected that each
controller will be a separate entity, or is there also a need to
consider controller partitioning? (Two different partitions on the same
access-node have an ANCP adjacency to the same controller)

	- Is there interest in enabling ANCP with "functional
partitioning"? 
	- In any partitioning scheme (hard of functional), is there a
need to allow for controller redundancy? 

	I hope that the above is sufficient to stimulate a discussion
and make some progress on the issue of partitioning. 

	Kind Regards, 
	Woj. 

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