Re: H323 mobility: Summary of discussion
Hi Radhika,
"Roy, Radhika R, ALARC" wrote:
Hi, Ed and All:
I understand your point. As I explained that contributions with solution have been provided based on "Home and Visited" solving the mobility problems.
All members are welcomed to provide solutions based on their concepts. If the alternate solutions are provided based on contributions we will definitely be able to see how solutions are provided based on alternate ideas or terminologies. Then, we will have wonderful opportunities to compare each idea or terminology without any confusion or ambiguity. Definitely we are waiting to make compromises if we collectively see that it makes sense to do so when we see that there are better solutions available based on alternative approaches.
We are only in definition phase. These are the place holders. If the architectural solution that we will be agreeing with does not support those definitions or terminologies we will definitely change these. There should not be any doubt about this. I do not see why we should hold-off our discussions for these two terms.
As an Editor, I suggest that you can put a note that "some members have some objection to agree on these two terms, but we will revisit these terms when we finalize our architectural solution."
Noted
We will have an architectural discussion in the upcoming conference call. We have invited contributions with proposed solutions to have all ideas clear so that we can move forward.
Finally, Ed - what we are looking for is the solution of the problem (not adding or deleting some terminologies here and there).
We have plenty to solutions, but weak definitions.
Thanks
Hope this email will clarify your concern.
Best regards, Radhika
-----Original Message----- From: Edgar Martinez [1] [SMTP:martinze@CIG.MOT.COM] Sent: Friday, November 05, 1999 6:31 PM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: H323 mobility: Summary of discussion
To the Mobile Ad-hoc Colleges:
What we have here is an opportunity to build a good working relationship. But, it seems at this time, we are in feeling out stage. Solutions and proposals are being worked within companies and in difference standards, which want to find a place in the work we are doing but, I think compromise is in order.
The only thing I was suggesting in by email, was that the word "Home and Visited" bother soon of our colleges. So my suggestion was to persevere the functions and compromise on the naming of the functions.
By definition, whatever we put in the H.323 mobility document will have to be in the context of the H.323 framework baseline.
Lets keep an open mind as we move forward, Y peace. We all may learn something and discover new things. If possible lets start looking on compromise solutions that satisfies all involved. Once we limit our scope it limits us from progressing towards the future.
Best Regards, Ed
"Roy, Radhika R, ALARC" wrote:
Hi, Ed and All:
I do not know whether you have seen my reply to Jaakko. I am enclosing
it
again. Please respond to my reply to provided Jaakko to prove your statement.
I completely disagree with Ed. Please also see Marc Roelands's comments
on
LA.
AT&T contribution has shown how H.323 mobility problem can be solved
using
home/foreign GK (zone).
I like to see the complete H.323 mobility problem that has been solved
using
the alternative approach as proposed by Nokia. I have NOT seen Nokia's solution yet. Unless a complete solution is provided like AT&T's, I am
NOT
convinced how mobility problem can be solved in a better way.
I also see that there is a need for HLF/VLF. No one against the HLF/VLF function. AT&T proposal also has shown how HLF/VLF function is taken care-of.
What I disagree with is this: A protocol should NOT be implementation specific. For example, we do have a luxury to build one protocol for distributive GK (HLF/VLF) function, one protocol for centralized GK (HLF/VLF) function or one protocol for hybrid GK (HLF/HLF) function. It
is
against the fundamental concept of H.323. For example, the same argument
can
also be applied for the directory function. Similar may the case for
other
functions as well. It is a complete break down of H.323 protocol and architecture.
So, HLF/VLF is another function in H.323. HLF/VLF is NOT a "Holy Grail"
for
which we have to create a complete "DISCONTINUITY" in existing H.323 protocol and architecture. I like see to Nokia's alternate solution to disprove this fear.
Nokia has to bring a complete contribution providing solution like
AT&T's to
prove their case. Otherwise, we cannot proceed with a concept that has
not
proved with a solution.
The problem can be solved as follows:
- Let Nokia provide a complete proposal solving the H.323 mobility
problem
using heir alternative approach. What Nokia has provided is a high level concept. They have NOT solved the problem yet. Let us see what the
complete
solution is. If a solution is provided, we can then compare Nokia's
solution
with that of AT&T's solution. Otherwise, their proposal is still HYPOTHETICAL. It is a concept, NOT a solution.
- How can we agree on a concept without seeing its solution that has
the
potential to break down the fundamental architecture of existing H.323 standard?
Let us solve H.323 mobility problem within the framework of H.323.
Let us move on with contributions for the part that we can agree on.
If
Nokia brings a complete solution, we will definitely re-consider their
case.
- I agree with you that we also need to work for interworking between
H.323
(IP) mobility and cellular-PSTN/ISDN network.
Finally, Ed - you have made a statement, but it has to be proved
providing a
solution. An alternative concept is there, but we have not seen its
solution
yet. What is the problem to bring the alternate solution? Why do we need
to
wait for a concept that has NOT been substantiated with a solution yet?
Best regards, Radhika
-----Original Message----- From: Edgar Martinez [1] [SMTP:martinze@CIG.MOT.COM] Sent: Thursday, November 04, 1999 9:47 AM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: H323mobility: Summary of discussion Importance: High
I agreed with most of Jaakko comments and also make vaild points, and will like to add the following.
I believe that the (Home) in Home Zone should be taken out. What we are talking about is the User's Point of Attached in any given Zone. The HLF is ready and Data base which has the User's profile and the current user's location. We can get a new name to HLF and call it the Location Profile Register (LPR) or Location Profile Function (LPF).
I also believe that the (Visited) in Visited Zone sould also be taken out because again we are talking about the Users current Point of Attachment in any given Zone. The VLF has the means to update the Location Profile Register (LPR) from any given Zone. We can get a new name to VLF call it the Location Update Register (LUR) or Location Update Function (LUF).
Now we can also support concepts of Zone ID's such as Current Zone ID and Previous Zone ID.
Finally,
And I strongly agree with looking at the interworking in parallel with H.323 mobility. The time we spent now looking at interworking will be compensated in the long run. I sure does working on ISUP, IN and Qsig, inetrworking with H.323 would agree and we should learn from their experience. And not leave it for a last minute add-on.
Lets take the contribution as they come, if one wants to put in interworking fine. If one wants to put in contributions only H.323 mobility also fine. Both are in order and within our scope.
The general strategy should focus on ensuring that the H.323 Mobility and interworking options are enabled, rather than spending too much effort blocking alternative options (Our limited resources frankly don't allow this luxury). But there really is no substitute
for
doing the work - preparing input papers and presenting them to move things forward.
Best Regards,
Ed
[Roy, Radhika R] Hi, Jaakko:
Pl. see my reply provided below.
Best regards, Radhika
-----Original Message----- From: jaakko.sundquist@NOKIA.COM[SMTP:jaakko.sundquist@NOKIA.COM]
Sent: Tuesday, November 02, 1999 11:13 AM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: H323mobility: meeting Once again, hi, Radhika, Ed + all See my comments below... Hi, Jaakko, Ed, and All: I hope that Jaakko will get this mail while heis in
his office (Thanks Jaakko - you have reminded us the time
difference)!
[Jaakko:] You caught me just in time. Please note the following: 1. Zone and domain are well defined in H.323. [Jaakko:] Yes, they are defined. 2. We have to work for mobility solution in away
that fits very well that already exists in H.323.
[Jaakko:] Agreed. 3. We can invent many things if we need to solvemobility problems only when we think that those functions are NOT covered in existing H.323 standard.
[Jaakko:] Yes. 4. If mobility problems can be solved using theconcept of "zones" and "domains," I would assume that it would be a big mile stone so far the continuity of H.323 is concerned. That is, as Ed pointed out, H.323 mobility problem is NOT a rocket science. We have to
remember
that we are working in the framework of already existing H.323 standard architecture. We have to relate our solution in the context of existing
H.323
standard. In other words, we CANNOT change the fundamental conceptof
existing H.323 standards just because we are addressing mobility.
[Jaakko:] Yes, of course. I'm not arguingagainst
that. I guess you are referring to the Location Area discussion here.
The LA
concept is really merely a scaling issue, you could of course handle
paging
(I'm assuming that we will need the paging procedure) based on zones, i.e. page every NPoA in a zone when a call arrives, but this might be
quite
limiting in some cases (the zone may be needlessly big or very small). I
do
not think that we need to change any fundamental concepts of H.323, if we introduce the LA concept. [Roy, Radhika R] May be we can include LA when we see that we
need
to optimize a zone further. We may revisit this in the second step.
5. I do not understand what benefits we aregaining
adding more "terminologies" like "AREA {home, foreign, etc}" while the "zone" and "domain" are already well defined in H.323. My personal view is that we should FIRST try to solve H.323 mobility
problems
within the context of "zone" and "domain" as far as practicable. I
would
argue that zone and domain are good enough to serve this purpose for now. (Pl. also see AT&T's and Motorola's contributions.)
[Jaakko:] As I already said, I did not intent todefine the terms: home area and visited area. I was just trying to
illustrate
the point I was making about not having the Home/visited zone terms
defined
yet. [Roy, Radhika R] It is good point. Let us define these. AT&T contributions have the detail definition for each term.
6. With respect to your comments that it appearsthat every GK will have HLF and VLF function, I would say that every GK will have the access to the HLF and VLF function. This capability for each GK
has to
be provided because of the fact that H.323 architecture is GK-centric.
We
do not have any choice because we are restricted by the H.323
architecture.
[Jaakko:] I did not argue against this. Thepoint is
that if we identify a concept called the Home Zone, this already implies that each User has only one zone, in which he/she/it is not a "visiting
user".
I think this would be really restricting. [Roy, Radhika R] As I mentioned that H.323 is the GK-centric. A user may change his/her network point of point attachment, but it is
still
the same (Home) GK. So, a given (home) GK, there has to be another level
of
granularity to address mobility in terms of network point of attachment. Please see AT&T contribution how home and foreign network concept have solved the problem. Similar is the case with Motorola's contribution.
The
bottom line is that home/foreign GK concept does NOT imply any
restriction
to solve H.323 mobility.
6.1 With respect to your question whetherHLF/VLF
can be distributive or centralized, having said (in item 5) that every
GK
should have access to HLF and VLF function, it is up to implementation
whether
HLF and VLF function can be centralized or distributive. Please see
AT&T
contributions submitted in Red Bank how we can implement these functionsin
both distributive and centralized environment.
[Jaakko:] This is actually quite much the pointI
was making. By defining the Home Zone we would in my mind actually
be
pointing to the centralized model. [Roy, Radhika R] By definition, there can as many GKs as one
wish
have in an H.323 system. So, by definition, the GK-centric H.323 architecture is distributive. By defining home/foreign GK, H.323
mobility
also becomes distributive up to the point that a basic H.323 system
allows
us. So, we do not see any limitations.
6.2 In an analogy of this HLF/VLF function, Ican
bring another function - Directory services. For example, H.323 assumes
that
all the address (e.g., alias, transport, network) are kept by each GK. H.323 does not answer how the address information is maintained by each
GK.
People are using LDAP directory server. The question is: whether that directory service is distributive or centralized? I guess that it can
be
done in both ways depending on implementation.
[Jaakko:] My point exactly. I would like thatall
GKs inside the same Administrative Domain would be able to access the same HLF/VLF functionality. [Roy, Radhika R] As I pointed out, this an implementation
issue. I
would argue that we should allow both options and let an implementor
choose
as it is necessary. Please also see AT&T contributions how both options
can
be addressed.
6.3 In AT&T contribution, it is shown that itbetter
to make VLF distributive (per GK) although HLF function can
be
made both distributive and centralized. Again, this is a matter of implementation. As mentioned in AT&T contribution, we also need to define a kind
of
backend protocol for VLF and HLF (something like similar to Siemens,
Nokia
and Intel's contribution - TD-39: Security Services for Backend Services
and
Mobility in H.323).
[Jaakko:] I would assume that you can distributethe
HLF/VLF functionalities inside the Administrative Domain as you like,
but
distributing them between the Domains would be difficult.Actually I
think that the concept of Administrative Domain was introduced in
H.323
for this kind of reasons. [Roy, Radhika R] Again, H.323 system is GK-centric in a given domain. For inter-domain, it is BE-centric. In a given domain, H.323 architecture has to be GK-centric. Once we solve intra-zone and
inter-zone
(intra-domain) mobility, we can extend our experience for inter-domain problem as well. Please also see AT&T contribution how these problems
have
been addressed. My replies to 6.1 and 6.2 are also good for this case.
7. Again, I, personally, do not rule our tore-examine the benfit of "AREA" (e.g. location area [LA]) vs. "ZONE/DOMAIN"
concept.
May be it is in the second step.
[Jaakko:] I am just a bit afraid that if weleave
this kind of a major mobility related concept out of the first phase
thinking
process, we will find it much more difficult to include the concept in
the
second phase (where I think we will need it). Furthermore, I'm not convinced that the LA concept would not be useful in the pure H.323 approach either. [Roy, Radhika R] I think that it can be place holder for now. I would request to bring more detail contributions proposing solutions
like
AT&T and Motorola to prove the case better. Then, we can compare both solutions. In AT&T contribution, I feel that the LA can be accommodated
to
optimize the zone further. So, I do not see that it is a problem to accommodate the LA concept if needed. I personally prefer that we can
better
address this in the second phase once we solve the problem for the basic architecture.
Hope that this email will clarify the thingsbetter.
[Jaakko:] I think the main thing is that we gotthe
discussion going on again. I'm kind of tired already, and I hopethat I didn't mess things up too much in this mail. [Roy, Radhika R] Definitely, I also like that discussions must
go
on. We must be convinced that we have the best solution because it has
the
severe implications for all on-going mobility standard works throughout
the
world once we standardize H.323 mobility in SG16.
Best regards, Radhika Same to you, Jaakko-- Edgar Martinez - Principal Staff Engineer Email mailto:martinze@cig.mot.com FAX 1-847-632-3145 - - Voice 1-847-632-5278 1501 West Shure Drive, Arlington Hgts. IL 60004 Public: TIPHON & Other Stds - http://people.itu.int/~emartine/ Private:TIPHON & Other Stds - http://www.cig.mot.com/~martinze/
-- Edgar Martinez - Principal Staff Engineer Email mailto:martinze@cig.mot.com FAX 1-847-632-3145 - - Voice 1-847-632-5278 1501 West Shure Drive, Arlington Hgts. IL 60004 Public: TIPHON & Other Stds - http://people.itu.int/~emartine/ Private:TIPHON & Other Stds - http://www.cig.mot.com/~martinze/
-- Edgar Martinez - Principal Staff Engineer Email mailto:martinze@cig.mot.com FAX 1-847-632-3145 - - Voice 1-847-632-5278 1501 West Shure Drive, Arlington Hgts. IL 60004 Public: TIPHON & Other Stds - http://people.itu.int/~emartine/ Private:TIPHON & Other Stds - http://www.cig.mot.com/~martinze/
participants (1)
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Edgar Martinez [1]