Hello Lily
-----Original Message-----
From: Yang, Lily L [mailto:lily(_dot_)l(_dot_)yang(_at_)intel(_dot_)com]
Sent: Monday, April 01, 2002 11:22 AM
To: Penno, Reinaldo [SC9:T327:EXCH]; Yang, Lily L; 'The Purple Streak
(Hilarie Orman)'; ietf-openproxy(_at_)imc(_dot_)org
Cc: Knight, Paul [BL60:1A00:EXCH]; 'pcs(_at_)eng(_dot_)registro(_dot_)br'
Subject: RE: [Pcs] Re: some questions and comments on draft-barbir-opes-sp
cs-01.txt
Reinaldo -- I am not fully convinced yet that you need to dynamically change
the rules for things like location services etc. In my mind, the changing
parameters do not necessarily mean changing rules. They are conceptually at
two different levels. The rules can be still quite static as to say "Apply
location service for User A at news.com and weather.com ", and then OPES
engine will send the actual location parameters to the callout server in
real time. So the callout server can use that dynamic information to adapt
the service accordingly. The same goes for the user profile, network
condition, etc. They are the parameters that callout server need to have,
but they don't need to be present at the rule level in the OPES engine --
rule is more about when to invoke what service for whom under what condition
Humm....the fact is that rules will change (even users can change some of
their "rules" at will today, this is true for content filtering). So, I
think maybe what we are discussing is if the OPES engine can have some
intelligence to or receive updates/compile/bypass the rules for certain
conditions or it would always send the content to the callout even if it
would say "I'm not going to do anything with that" ; or receive the rules
pre-compiled by the admin server.
For example, this "condition" could be for instance where you are located,
what is the status of the network, what device you are using, etc. You could
have a rule saying "apply this rule only if I'm at most 30 milles from my
house". Do you consider this a static rule (the engine need to know if you
are at most 30 milles from your house even to apply the rule in the first
place)? Or, "if I'm indoors do not adapt my weather service". Or "apply
this rule only if my bandwdith is X or my profile is Y".
regards,
Reinaldo
, but it doesn't deal with the specific adaptation intelligence inside each
service. The service itself deals with such detail -- so the video
transcoder would decide what frame rate, bit rate to use under what kind of
network condition, the location service would decide the location
granularity it use to adapt the content, the personalization service would
decide what info it uses from the user profile to adapt the contet, etc. I
think separating those service-specific detail out from the OPES rule engine
is beneficial in several ways. It provides scalability by keeping the OPES
rule base size manageable and stable while allowing the callout server to
change its internal implementation intelligence without affecting the OPES
engine most of time. It probably can avoid requirements like dynamic rule
loading all together (I am just guessing without any detail analysis yet)
which certainly simplifies things a lot and also helps the performance.
Lily
-----Original Message-----
From: Reinaldo Penno [mailto:reinaldo_penno(_at_)nortelnetworks(_dot_)com]
Sent: Monday, April 01, 2002 11:01 AM
To: Yang, Lily L; 'The Purple Streak (Hilarie Orman)';
ietf-openproxy(_at_)imc(_dot_)org
Cc: Paul Knight; 'pcs(_at_)eng(_dot_)registro(_dot_)br'
Subject: RE: [Pcs] Re: some questions and comments on draft-barbir-opes-sp
cs-01.txt
Hello Lily,
the dynamic loading of rules need to occur even without personzalition. For
instance, in the case of location based services (news, weather, etc) where
the user is mobile, we need to dynamically load rules (whether in the
callout server, whether in the intermediary) in real time.
Services like virus scanning and content filtering are pretty static in
relation to the rules, but services that depend on changing parameters like
the location of the user, current performance of the network (bandwidth,
jitter, etc), user profile, and others need dynamic rules anyway.
regards,
Reinaldo
-----Original Message-----
From: Yang, Lily L [ mailto:lily(_dot_)l(_dot_)yang(_at_)intel(_dot_)com
<mailto:lily(_dot_)l(_dot_)yang(_at_)intel(_dot_)com> ]
Sent: Monday, April 01, 2002 10:14 AM
To: 'The Purple Streak (Hilarie Orman)'; ietf-openproxy(_at_)imc(_dot_)org
Cc: Knight, Paul [BL60:1A00:EXCH]; 'pcs(_at_)eng(_dot_)registro(_dot_)br'
Subject: RE: [Pcs] Re: some questions and comments on
draft-barbir-opes-sp cs-01.txt
Hilarie -- Maybe you are right to call it a matter of terminology than
architecture. But I am a bit confused now about the role of
Admin server and
the callout server and how much now they overlap with each
other. I am also
concerned about the performance implication of dynamically
loading rules to
the OPES engine by callout server in the content path in real
time. In a
separate thread, you mentioned the slow XML parsing
performance. Whether or
not that is indeed true remains an ipen issue. But having the
callout server
dynamically loading the rules onto the OPES engine requires
that the rules
being transported over the wire is in standard formats (IRML?)
instead of
the internal format between the Admin Server and the OPES engine. That
imposes some extra (XML?) parsing overhead in the content path.
All these have implications that I think deserve some careful
consideration
in the requirement gathering phase.
Lily
-----Original Message-----
From: The Purple Streak (Hilarie Orman) [
mailto:ho(_at_)alum(_dot_)mit(_dot_)edu
<mailto:ho(_at_)alum(_dot_)mit(_dot_)edu> ]
Sent: Thursday, March 28, 2002 2:38 PM
To: ietf-openproxy(_at_)imc(_dot_)org
Cc: 'paknight(_at_)nortelnetworks(_dot_)com';
'pcs(_at_)eng(_dot_)registro(_dot_)br'
Subject: [Pcs] Re: some questions and comments on
draft-barbir-opes-spcs-01.txt
This seems like a matter of terminology more than architecture.
The OPES intermediary can trigger on the event "begin user
session" and have the action "notify personalization server" or
"notify user services admin server" as basic policy rules. The
communication can use the OPES callout protocol, and the returned
items can be rules. OPES policy can state that rules are
only accepted
from a trusted callout server list, and they can implement the policy
that the returned rules can apply only to the user session for which
the callout server was invoked. This doesn't seem particularly
dangerous. It does put more requirements on the OPES engine
to enforce
local policy, but I thought it was going to be a policy enforcement
engine, anyway.
Hilarie
Yang, Lily L wrote:
Hi, Paul --
Just went through draft-barbir-opes-spcs-01.txt. Sorry that
I couldn't do
that earlier -- Looks like I got a lot to catch up.
First of all, I am not sure that I fully understand the
exact role of the
OPES Service Personalization Callout Server (SPCS) and how
it should be
treated in the OPES framework. My understanding of the
draft is that, to
achieve service personalizaiton, we actually need to deploy
two kinds of
callout servers within the OPES framework. One is the SPCS,
its role is to
generate dynamic rule modules to upload onto the OPES
intermediary based
upon subscriber profile and content profile. But the actual
rules (which are
dynamically generated by SPCS) will possibly invoke some
content adaptation
service that is to be carried out by the Callout Server
(per the diagram
depicted in Figure 1 on page 12). These Callout Servers are
the second kind
of callout servers. At the surface, both are callout
servers and should be
treated as such by the OPES framework. However, they are
VERY different in
what they actually do.
In my mind, callout servers only do adaptation service for
the content, they
don't control/alter the behavior of OPES intermediary (the
engine). So only
the second kinds are the real callout servers in that
sense. The first kind
(SPCS) is not, at least not according to my understanding
of the callout
server definition. Allowing a callout server to dynamically
upload or delte
rules from the OPES engine sounds like asking trouble to
me. Allowing them
to adapt the content is already a riksy business! This is
10 times worse
than that. To me, SPCS sounds much more like one instance
of the OPES admin
server. Admin Server is the entity that can control/alter
the behavior of
OPES engine and it requires a much tighter security/trust
model between the
Admin Server and the OPES engine. .
The description of the SPCS's functions are very much the
same as the Admin
Server, but with some important exceptions -- the purpose
of SPCS is much
narrower of the Admin Server; and there is the "real-time,
in the content
path" aspect of SPCS that is not required (in general) by
the Admin Server.
My understanding is that SPCS needs to generate and upload
the dynamic rules
in real time at the beginning of the "SP-session", and then
SPCS is not
involved for the rest of the session before its
termination, is it correct?
At the middle of the session, the rules that is just
uploaded would govern
the actual content adaption (for personalization). It seems
that somewhere
the text also suggests the profile might change mid-session
and does that
mean the rules will be generated again mid-session?
Maybe I misunderstand the whole concept -- otherwise, I
have some serious
concern about some of these issues.
Lily
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