Subject: [DMM] FW: enhanced anchor teleconference - notes

From: h chan <[email-masked]>
Date: Mon, 20 Oct 2014 02:47:08 +0000

The following attended the enhanced anchor team teleconference on Oct 10 at 7-8AM pacific time.
Satoru Matsushima, Fred Templin, Alper Yegin, Marco Liebsch, Kostas Pentikousis, Anthony Chan

Anthony (AC): Introduction: Different DMM solutions are using anchors. They are using different names for the anchor. While the names may be different, the description of what it does ought to have similarities among. It is therefore suggested to first ask what are the functions of anchor and try to identify what are common among them. We might be able to further categorize different mechanisms in using the anchor.

Alper (AY): Like it, define various attributes of anchors.

AC: Examples are: draft-seite-dmm-dma called it MAR (mobility capable access router), and the functions include forwarding by tunneling, allocating IP prefix/addr, Advertize prefix plus location update. draft-bernardos-dmm-pmip called it MAAR, and the functions include forwarding by tunneling, allocation IP prefix/address, prefix advertisement and location update (in conjunction with a centralized mobility database). There are several other examples.

AY: IP anchor is a functional entity which can be located everywhere: it allocates IP address, and it advertise prefixes. Another element of the anchor is host-specific forwarding entry.

Fred (FT): Do we assume a Mobile IP type of model? Can the anchor talk to MN, or can it talk to MAG?

AY: We have not talked about the distinction between network-based and host-based protocols yet.

Discussion agreed to include both network-based and host-based mobility.

FT: Then for host-based solution, the traffic in the case of route optimization (directly between MN and CN) does not traverse through the above anchor.

Marco (ML): There is also a Control-Plane anchor.

AY: True. Don't enter the discussion of other WTs.

AC: This discussion so far lists both data plane function and control plane function.

AY: Ok, let's recognize that there are so far two entities, Control and Data Plane. They may be collocated or separated.

Discussion agrees to separately list the functions in the data plane and those in the control plane. It enables separating data and control planes but it does not exclude the cases where they are combined as in the mobility protocols in the past.

AY: ... routers have a specific name, e.g. deflector. Host specific forwarding entries.

(FT: has to leave)

..discussion about lose definition of anchor (entity applying flow/host policies for traffic), the model applies to any RO traffic case. Even endpoints can function as anchor (MIP6 RO).

ML: multiple anchors to be considered. MAG to even CN can anchor traffic in case of RO.

AY: Can do this, but that deviates from understanding so far.

AC: Another example of multiple anchors is in draft-matsushima-stateless-uplane-vepc .

Question on whether the traffic in this draft is symmetric or asymmetric (UL/DL)

AY: Discuss where such anchor function can be located. There can be multiple anchors, and not just a single anchor.

Discussion agrees that it is not necessary to have a single anchor for a given prefix. There may be multiple anchors for the same IP prefix (as in the case of anycast and in the case of BGP)

AC: There is an information element such as binding or a mobility database and with location update function in the control plane.

AY: That is the forwarding entry.

Discussions: It appears that the terms IP anchor and mobility anchor had been used, but they have remained undefined.

ML: anchor definition moves more towards legacy function of router/switch, which carries state for MN (per-host or aggregated).

AY: draft-mccann-dmm-flatarch uses BGP. More than one router can have a per-host state.

AC: Conclusion? Time schedule is tight. Charter requires to submit first draft in February.

AY: Let's produce the WT output.

AC: We may start with the functions of the anchor. The next may be to explain the different ways of using the anchor to support mobility.

.. discuss

Discussion agrees that Discovery mechanism is in this WT. It means discover the identity of the anchor and its capabilities.

AC: It is desirable to categorize different mechanisms of using the anchor.

AY: There are 3 categories to locate the anchor, Anchoring in the MN's access network, correspondent node's network, and at the corresponding node itself.

AY: After discovery, there is signaling.

Notes taken by Marco, edited by Anthony.

H Anthony Chan