Subject: RE: [Sigtran] How should an AS be viewed ?

From: "Duhoon, Rajiv" <[email-masked]>
Date: Tue, 26 Feb 2002 20:21:07 -0800

Brian,

See my comments below.

Right now I want to discuss the case where
both the SGPs (SGP1 & SGP2) are not part of
the same SG.

-----Original Message-----
From: Brian F. G. Bidulock [mailto:[email-masked]]
Sent: Tuesday, February 26, 2002 1:20 AM
To: Duhoon, Rajiv
Cc: [email-masked]'
Subject: Re: [Sigtran] How should an AS be viewed ?

Rajiv,

If SGP1 and SGP2 belong to different SGs there is no requirement
to coordinate the RC values between SGs and View 1 is permitted.
If SGP1 and SGP2 belong to the same SG, there was a requirement
in the spec which says that these SGP "SHOULD" coordinate RC
values across SGP belonging to the same SG and View 2 is required.

Even if the SGP do not belong to the same SG, if the SGs are
acting as mated STPs, one would expect View 2 to prevail although
it is not required by the spec.

Does that mean that the routing key(as in example)configured at
SGPS should map to  single AS and RC. Shouldn't RK:AS mapping be kept
unique on per SGP:ASP basis. I think AS concept is
required at SGPs only and its the SGPs who will define the AS for
routing purposes. ASP doesn't need to define any AS. ASP just need to
know about the corresponding RC and should maintain a list of RC per
SGP basis. That way view seems to be right one.

In view 2 ASP is defining an AS and indicating to SGPs that ASP can 
serve this AS thus putting a restriction on RCs to be used by SGP
as there is a condition of 1:1 mapping beween AS & RC.

In View 1 AS1 and AS2 can have their independent mapping with RC1 & RC2 as
would be required in case of dynamic registration procedures.

Do these SGP belong to the same SG?
[Rajiv] SGP do not belong to same SG. I want to know that in such
a case are they allowed 

--brian

Duhoon, Rajiv wrote:                                      (Mon, 25 Feb 2002
17:15:02)
> Hi All,
> 
> If an ASP  have an  ISUP user and two  SGPs SGP1 and SGP2
> as shown in the diagram wants to send ISUP traffic to
> this ASP then  which of the following AS view is
> correct as per M3UA Draft ?
> 
> Following configurations has been defined as per M3UA Draft stating
> that each RK is 1:1 mapped with AS, each RK is 1:1 mapped with RC
> & therefore AS is also 1:1 mapped with RC.
> 
> 
> ----------------------------------------------------------------------
> View 1:
> ASP serving two independent AS (AS1 & AS2) for same routing key at two
> SGPs:
> 
> Routing Key (RK1)   -  DPC = 300, OPC = *, SIO = ISUP, CIC = *
> 
> At SGP1
> AS1 --map to --> RK1 --map to --> RC1
> 
> At SGP2
> AS2 ---map to --> RK1 ----> RC2
> 
> ASP1 goes active for both of these SGP(s) by generating two
> independent ASP ACTIVE messages with RC1 & RC2 as routing context
> parameter.
> 
>            PC = 100            
>      +-------------+  
>      |       +---+ | 
>      | SGP1  |AS1 ||--------+           +-------------+
>      |       +---+ |        |           |             | 
>      +-------------+        |-----------|  ASP1       |
>                             |           |             |
>                             |           +-------------+  
>                             |                 PC = 300
>      +-------------+        |
>      |       +---+ |        |
>      | SGP1  |AS2| |--------+      
>      |       +---+ |
>      +-------------+  
>           PC = 200
> 
> -------------------------------------------------------------------------
> 
> Routing Key (RK1)   -  DPC = 300, OPC = *, SIO = ISUP, CIC = *
> 
> View 2:
> ASP serving single AS for a single routing key at both the SGPs
> 
> Routing Key (RK1)   -  DPC = 300, OPC = *, SIO = ISUP, CIC = 100 - 200
> 
> At SGP1
> AS1 -- map to --> RK1 -- map to --> RC1
> 
> At SGP2
> AS1 --- map to --> RK1 -- map to --> RC1
> 
> ASP1 goes active for both of these SGP(s) be generating two independent 
> ASP ACTIVE messages with same Routing Context RC1 as routing context
> parameter
> 
> 
>            PC = 100            
>      +-------------+  
>      |       +---+ | 
>      | SGP1  |AS1| |--------+          +-------------+
>      |       +---+ |        |           |+---+        | 
>      +-------------+        |-----------||AS1|  ASP1  |
>                             |           |+---+        |
>                             |           +-------------+  
>                             |                 PC = 300
>      +-------------+        |
>      |       +---+ |        |
>      | SGP1  |AS1| |--------+      
>      |       +---+ |
>      +-------------+  
>           PC = 200
>
----------------------------------------------------------------------------
> ----
> 
> With in a network for one routing key (e.g RK1 defined above) served by an
> ASP, is
> allowed to have  multiple independent AS defined on different SGP(s) as in
> View 1 or all 
> the SGPs should have a common view of a single AS served by ASP as defined
> in View 2.
> 
> In my opinion  1:1 mapping or RK:AS, RK:RC, AS:RC should be true at SGP as
> in view 1
> and not as in view 2. SGP should be allowed to define independent AS for
> there routing
> needs.
> 
> Thanks,
> Rajiv
> 
> 
> _______________________________________________
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> [email-masked]
> https://www1.ietf.org/mailman/listinfo/sigtran

-- 
Brian F. G. Bidulock
[email-masked]
http://www.openss7.org/

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