Subject: RE: [Dime] assure proxies can remain in the path of allrequestsinasession?

From: "Ram O V Vishnu-A14676" <[email-masked]>
Date: Thu, 13 Apr 2006 18:15:35 +0800

I think in this case, if you are particular that the message should pass
through the specific proxy, you should have the proxy as the destination
host of the (non-first) message. 

Anyways (since you are saying that) the proxy is stateful &  keeps per
session state, it can also keep the consistent routing info? (as Tolga
pointed out earlier). This will make sure that the proxy is able to
route to the next hop as well consistently.

Regards,
Vishnu.

Motorola India Electronics Pvt Ltd
+91 9844178052
[*] Motorola Internal Use Only

-----Original Message-----
From: zhangtao [mailto:[email-masked]] 
Sent: Thursday, April 13, 2006 6:40 AM
To: Tolga Asveren; [email-masked]
Subject: Re: [Dime] assure proxies can remain in the path of
allrequestsinasession?

Think about below situation:
Client - Relay Agent - Proxy Agent1 - Server
                                -  Proxy Agent2 
client directly connection to realy agent.realy agent connection two
proxy agent(Prxoy agent1 and Proxy agent2),both proxy agent can route to
server.

Non -First Message is base on Destion-Host,only can assure Go to the
same server,but cannot assure route to same prxoy agent(maybe all
agent).when client send message ,in peer table cannot find server,then
will use Destion Realm,if have two peer entry in the route entry,it can
select any one.maybe we can think about client record his first message
of a session.then he use same Next Hop. but if have relay agent,how to
do,we cannot requirment,realy agent record any information about
session. so the message it can select proxy agent1 or proxy agent2.
assume first session message route by proxy agent1. non first session
message route by prxoy agent2,then proxy agent1 maintain session state
will bring problem.

----- Original Message ----- 
From: "Tolga Asveren" <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, April 12, 2006 7:58 PM
Subject: RE: [Dime] assure proxies can remain in the path of all
requestsinasession?

> > In my Idea,now Diameter Message routing  base on Destination Realm 
> > and Destination Host.if one route entry  have two peer entry,it 
> > cannot assure start session use first Peer,the stop session will use

> > first peer also.
> [TOLGA]The behavior you described is achieved by populating 
> Destination-Host AVP for the non-first messages of a session. this 
> assures that all of them land on the same node.
> 
> 
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> DiME mailing list
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> https://www1.ietf.org/mailman/listinfo/dime

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---

From: Victor Fajardo <[email-masked]>
Date: Wed, 12 Apr 2006 18:07:39 -0400

Hi,
> route to the next hop as well consistently.
In the sip case, strict routing is not always possible because operators 
normally deploy multiple agents for load balancing/redundancy. hence, 
subsequent request are not guaranteed to go through the same routing 
path as previous request. One contradiction is that load balancing is 
less effective if strict routing is allowed.

regards,
victor

---

From: "Tolga Asveren" <[email-masked]>
Date: Thu, 13 Apr 2006 09:08:56 -0400

Hi Victor,

> From: Victor Fajardo [mailto:[email-masked]]
> Sent: Wednesday, April 12, 2006 6:08 PM
> To: Ram O V Vishnu-A14676
> Cc: zhangtao; Tolga Asveren; [email-masked]
[TOLGA]I couldn't get the exact scenario here. By saying "sip case" and
"agents" are you referring to SIP entities or Diameter entities? -a simple
diagram would be appreciated :-) -

---

From: Victor Fajardo <[email-masked]>
Date: Thu, 13 Apr 2006 09:35:23 -0400

Hi Tolga,
> diagram would be appreciated :-) -

Since I'm not good a drawing diagrams you can take a look at 
draft-ietf-aaa-diameter-sip-app-11.txt :) ... they have excellent 
diagrams :)

regards,
victor

---

From: "Tolga Asveren" <[email-masked]>
Date: Thu, 13 Apr 2006 09:30:09 -0400

Hi Victor,
> draft-ietf-aaa-diameter-sip-app-11.txt :) ... they have excellent
[TOLGA]Considering Figure1 in that document, load balancing/redundancy for
which entity (Proxy1, Proxy2, Diameter Server) would cause a problem and for
whaht type of scenario/message flow?

---

From: Victor Fajardo <[email-masked]>
Date: Thu, 13 Apr 2006 11:15:54 -0400

Hi Tolga,
>>>> In the sip case, strict routing is not always possible because
>>>>         
>> operators
>>     
>>> "agents" are you referring to SIP entities or Diameter
>>>       
>> entities? -a simple
>>     

Good question. Apologies for my terse explanations :) From what I've 
read on certain sip deployments (maybe i'm wrong), SIP server1 in figure 
1 can actually be represented by an AAA routing cloud that could contain 
the diagram described by zhaotao, a client->relay->(proxy1,2,3). the AAA 
client of the SIP server can send request to the relay which passes can 
pass the request to any available proxies based on some redundancy or 
load-balancing schemes. But it can break things since the proxy also 
needs to maintain state as mentioned previously. In a more extended 
case, SIP server1 in figure 1 may also represent AAA routing across 
domains and each domain may have a combination of relays and proxies 
that want to account for SIP transactions going through them. This maybe 
in the case that the SIP clients is roaming and some intermediate domain 
between visited and home domains wants to keep accounting records. 
Anyway, it maybe a matter of setting up topologies strictly and 
correctly but that normally puts a damper on load-balancing.

my 2 cents,
victor

---

From: zhangtao <[email-masked]>
Date: Fri, 14 Apr 2006 10:06:37 +0800

I also think this is one solution.
but if the first message of session already give Destination-Host(Maybe this information get from SIM or others,but it can happen) and Destination Realm.this message route by many Proxy agents.then non-first message use first proxy agent's host as  Destination-Host(i am not assure should change Destination Realm or not).
then in one session,have two different Destination Host.the other question is :when routeing on  proxy agent,the proxy agent should change the message's original host or not,because the server maybe initiate reqeust message.

----- Original Message ----- 
From: "Ram O V Vishnu-A14676" <[email-masked]>
To: "zhangtao" <[email-masked]>; "Tolga Asveren" <[email-masked]>; <[email-masked]>
Sent: Thursday, April 13, 2006 6:15 PM
Subject: RE: [Dime] assure proxies can remain in the path of allrequestsinasession?

Regards,
Vishnu.

-----Original Message-----
From: zhangtao [mailto:[email-masked]] 
Sent: Thursday, April 13, 2006 6:40 AM
To: Tolga Asveren; [email-masked]
Subject: Re: [Dime] assure proxies can remain in the path of
allrequestsinasession?

----- Original Message ----- 
From: "Tolga Asveren" <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, April 12, 2006 7:58 PM
Subject: RE: [Dime] assure proxies can remain in the path of all
requestsinasession?