Hi Qin, Thanks for your comments on this bitmap ID. Please see replies below. BR, Mohana > -----Original Message----- > From: Qin Wu [mailto:sunseawq at huawei.com] > Sent: Monday, October 26, 2009 8:56 PM > To: Mohana Jeyatharan; netext at ietf.org > Subject: Comments on draft-jeyatharan-netext-pmip-bulkpbu-bitmap-00.txt > > Hi, Mohana: > I read your I-D about bitmap based PBU and would like to have some > comments as follows: > It seems to me the Bulk PBU using Bitmap is one robust header/packet > compression mechanism. > in other words, Bulk PBU can be further compressed or optimized using > Bitmap which saves > not only signaling but also packet size comparing with Bulk re- > registration mechanism described > in draft-premec-netlmm-bulk-re-registration-03. [Mohana] Yes, as you have mentioned the bitmap based approach is not only reducing number of signals but also a mechanism to reduce packet size. The mechanism in draft premec-netlmm-bulk-re-registration is for re-registration and de-registration of a group of MN's that belong to a certain group identified by a group identifier. However the bit map approach is a general approach that can be used with or without the group ID approach. Furthermore the bitmap approach is not restricted to bulk re-registration or bulk de-registration scenarios. It is more of bulk PBU... However I agree that for bulk re-registration of a group, the ideal way is to use a group ID to refresh the bindings. > But what I am still difficult to understand is in which situation or > scenario the Bitmap based > Bulk PBU will be utilized instead of Bulk re-registration ? > > As you said in the I-D, The PBU originating from the MAG can be of > different types > such as initial registration PBU, handoff PBU, re-registration PBU and de- > registration PBU. > If the PBU originating from the MAG is initial registraion PBU, how can > you guarantee that > MAG initializing Bulk PBU can be attached by several Mobile nodes at the > same time > during initial registration for all these mobile nodes? [Mohana] Bulk attachments to a MAG can take place in many practical scenarios. For example many users performing initial attachment at the same time. A densely populated urban area or train station etc, we may experience a bulk arrival of initial attachment messages. Without attachment > by several mobile > nodes simutanesouly, how does the MAG construct bitmap base Bulk PBU > packet? [Mohana] Yes, the MAG needs to check its state and identify such multiple simultaneous registrations from numerous MNs and plan the PBU. The MAG should construct the bulk PBU using bitmaps to compress the bulk PBU. I think > the same applies to handoff PBU. [Mohana] The same for handoff. There can be cases where multiple MNs attach to certain MAG due to handoff. This can happen in real cases. I agree to some extent that the > > If the PUB originating from the MAG is re-registraion PBU, I am afraid > that the most efficient > or optimized way is to only carry Bulk Set ID or grouped ID in the re- > registration PBU, the > other mobility options is not necessary to be included, because LMA has > already maintained > binding for all these mobile nodes pertained to Bulk Set ID or grouped ID. > In this scenario, > if we still choose to use bitmap based PBU, more packet size will be > costed for bitmap option included. [Mohana] Well, I agree that for re-registration PBU, once all nodes have joined a group, the group ID is ideal way. Infact, in such cases we have mentioned that in section 3, that if multiple group IDs are used then probably the bit map option can be used in case there are multiple re-registration taking place for these group IDs at the same time. Here the bitmap approach is highlighted as interworking with group ID approach, which is ideal for re-registration PBus. > The same applies to de-registration PBU. [Mohana] For the de-registration case, if we are sure that all deregistration can be tied to one group, then group ID based approach is more of a neater way of doing it. What if random movement from the service area of MAG. Then the MN deregistration pattern cannot be grouped into a single group ID. In such a case, the bitmap approach can be used. However I agree that as mentioned in draft-premec-bulk-registration, if LMA uses blade architecture and all MNs are tied to groups, then deregistration only needs the MN group identifier. This is deterministic grouping. I think for random grouping bitmap way can be used. > Therefore the only two pratical scenarios occuring to me instead of using > Bulk re-registration are > a. Bitmap based Bulk PBU can be used when several MNs ask to be added into > Bulk re-registration set. > b. MAG sending a Bitmap based bulk PBU containing several Bulk Set IDs > created during the Bulk > re-registration and several other Individual mobile nodes who would like > to be added to one specific > bulk re-registration set. > In these two scenarios, bitmap based PBU can be used to compress packet > size of PBU that includes > several MNs who ask to join several bulk re-registration sets by avoiding > duplicate mobility options for different > MNs. > > Am I right? [Mohana] Yes, you are absolutely right. Thanks for pointing out these two scenarios. Another scenario is where there is a LMA failure and the MAGs choose another LMA. Another scenario is bulk deregistration of MNs that do not belong to an MN group identifier as mentioned previously. > > Regards! > -Qin > ----- Original Message ----- > From: "Mohana Jeyatharan" <Mohana.Jeyatharan at sg.panasonic.com> > To: <netext at ietf.org> > Sent: Friday, October 16, 2009 9:13 AM > Subject: [netext] FW: I-DAction:draft-jeyatharan-netext-pmip-bulkpbu- > bitmap-00.txt > > > Hi all, > > This ID is highlighting a bulk PBU optimization approach using bit maps. > > This approach can be used to send multiple PBU signals of any type in a > combined manner using bitmaps. This approach can work along with the MN > group ID approach as well as highlighted in this draft. > > Please see. > > Comments are appreciated. > Thanks. > > BR, > Mohana > -----Original Message----- > From: i-d-announce-bounces at ietf.org > [mailto:i-d-announce-bounces at ietf.org] On Behalf Of > Internet-Drafts at ietf.org > Sent: Friday, October 16, 2009 9:00 AM > To: i-d-announce at ietf.org > Subject: I-D Action:draft-jeyatharan-netext-pmip-bulkpbu-bitmap-00.txt > > A New Internet-Draft is available from the on-line Internet-Drafts > directories. > > Title : Bulk PBU using Bitmaps > Author(s) : M. Jeyatharan, C. Ng > Filename : > draft-jeyatharan-netext-pmip-bulkpbu-bitmap-00.txt > Pages : 8 > Date : 2009-10-15 > > In Proxy Mobile Internet Protocol version 6 (PMIPv6), each mobile > node attached to a mobile access gateway (MAG) requires separate > signaling. This might result in excessive network signaling if there > a large number of mobile nodes attached to a MAG. In this draft we > outline a bulk PBU optimization approach based on bitmap, in order to > reduce the signaling load tied to numerous PBUs originating at the > same time. > > A URL for this Internet-Draft is: > http://www.ietf.org/internet-drafts/draft-jeyatharan-netext-pmip-bulkpbu > -bitmap-00.txt > > Internet-Drafts are also available by anonymous FTP at: > ftp://ftp.ietf.org/internet-drafts/ > > Below is the data which will enable a MIME compliant mail reader > implementation to automatically retrieve the ASCII version of the > Internet-Draft. > > > > ------------------------------------------------------------------------ -- > ------ > > > > _______________________________________________ > > netext mailing list > > netext at ietf.org > > https://www.ietf.org/mailman/listinfo/netext > >
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