Hi, Few quick comments. I would remove all explicit references to 3GPP and existing offload mechanisms therein. FWIW this WG is not supposed to be a stub of SA2. The possible (protocol) enhancement must be generic enough to be applicable outside of a specific deployment architecture.
Also, I think we ought not only consider just mobility enhancement. More efficient use of CoA(s) for direct/local/non-tunneled communication along with existing mobility solutions should be in scope as well. - Jouni On Oct 28, 2011, at 3:21 PM, Jari Arkko wrote: > And a follow-up on the charter. I'm describing a couple of different takes on > what the new charter could be. Comments and alternative proposals are > welcome. This is what the current charter says about DMM: > >> The working group will also work on operational considerations on >> setting up Mobile IPv6 networks so that traffic is distributed >> in an optimal way, for instance by using existing protocol mechanisms >> to select the closest home agents for new clients. >> >> Oct 2011 - Submit I-D 'Operational considerations for distributed use of >> Mobile IPv6' for publication as Informational. > > Which is admittedly a bit short, but is also very concrete and achievable, if > we work on it. I got another proposal from Hui Deng that extended this a bit, > including going beyond mere operational considerations. > >> In the past decade a fair number of mobility protocols have been >> standardized. Although the protocols differ in terms of functions and >> associated message format, we can identify a few key common features: >> presence of a centralized mobility anchor providing global reachability and >> an always-on experience >> extensions to optimize handover performance while users roam across wireless >> cells >> extensions to enable the use of heterogeneous wireless interfaces for >> multi-mode terminals (e.g. cellular phones) >> The presence of the centralized mobility anchor allows a mobile device to be >> reachable when it is not connected to its home domain. The anchor, among >> other tasks, ensures forwarding of packets destined to or sent from the >> mobile device. As such, most of the deployed architectures today have a >> small number of centralized anchors managing the traffic of millions of >> mobile subscribers. >> >> To optimize handovers for mobile users, the base protocols have been >> extended to efficiently handle packet forwarding between the previous and >> new points of attachment. These extensions are necessary when applications >> impose stringent requirements in terms of delay. Notions of localization and >> distribution of local agents have been introduced to reduce signalling >> overhead. Unfortunately today we witness difficulties in getting such >> protocols deployed, often leading to sub-optimal choices. Moreover, all the >> availability of multi-mode devices and the possibility to use several >> network interfaces simultaneously have motivated the development of more new >> protocol extensions. >> >> Mobile users are, more than ever, consuming Internet content, and impose new >> requirements on mobile core networks for data traffic delivery. When this >> traffic demand exceeds available capacity, service providers need to >> implement new strategies such as selective traffic offload (e.g. 3GPP work >> items LIPA/SIPTO) through alternative access networks (e.g. WLAN). Moreover, >> the localization of content providers closer to the Mobile/Fixed Internet >> Service Providers network requires taking into account local Content >> Delivery Networks (CDNs) while providing mobility services. >> >> As long as demand exceeds capacity, both offloading and CDN techniques could >> benefit from the development of more flat mobile architectures (i.e., fewer >> levels of routing hierarchy introduced into the data path by the mobility >> management system). This view is reinforced by the shift in users’ traffic >> behaviour, aimed at increasing direct communications among peers in the same >> geographical area. The development of truly flat mobile architectures would >> result in anchoring the traffic closer to point of attachment of the user >> and overcoming the suboptimal routing issues of a centralized mobility >> scheme. >> >> While deploying today’s mobile networks, service providers face new >> challenges. More often than not, mobile devices remain attached to the same >> point of attachment, in which case specific IP mobility management support >> is not required for applications that launch and complete while connected to >> the same point of attachment. However, the mobility support has been >> designed to be always on and to maintain the context for each mobile >> subscriber as long as they are connected to the network. This can result in >> a waste of resources and ever-increasing costs for the service provider. >> Infrequent mobility and intelligence of many applications suggest that >> mobility can be provided dynamically, thus simplifying the context >> maintained in the different nodes of the mobile network. >> >> The proposed charter will address two complementary aspects of mobility >> management procedures: the distribution of mobility anchors to achieve a >> more flat design and the dynamic activation/deactivation of mobility >> protocol support as an enabler to distributed mobility management. The >> former has the goal of positioning mobility anchors (HA, LMA) closer to the >> user; ideally, these mobility anchors could be collocated with the first hop >> router. The latter, facilitated by the distribution of mobility anchors, >> aims at identifying when mobility must be activated and identifying sessions >> that do not impose mobility management -- thus reducing the amount of state >> information to be maintained in the various mobility anchors of the mobile >> network. The key idea is that dynamic mobility management relaxes some >> constraints while also repositioning mobility anchors; it avoids the >> establishment of non optimal tunnels between two anchors topologically >> distant. >> >> Considering the above, the working group will: >> >> Define the problem statement and associated requirements for distributed >> mobility management. This work aims at defining the problem space and >> identifies the key functional requirements. >> >> Produce a gap analysis mapping the above requirements against existing >> solutions. >> >> Give best practices for the deployment of existing mobility protocols in a >> distributed mobility management and describe limitations of each such >> approach. >> >> Describe extensions, if needed, to current mobility protocols for their >> application in distributed mobility architectures > > Comments? > > Jari > > _______________________________________________ > MEXT mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/mext _______________________________________________ MEXT mailing list [email protected] https://www.ietf.org/mailman/listinfo/mext
