Re: AS concepts and Relay in SUA and M3UA

Stanislav,

The relay capability is a function of SCCP, just as the transfer
function is a capability of MTP.

M3UA cannot support the transfer function at an ASP or IPSP (only at an
SG, and then within the SS7 doamin).  The problem is that M3UA does not
support interworking of the necessary management messages for an ASP or
IPSP to be able to support the transfer function.  Thus we left it out
of the M3UA RFC to be dealt with by an extension draft, which never came
to fruition.  See Tolga's draft for the state of affairs there.

SUA, on the other hand, can support the relay function at ASP, IPSP and
SG.  All of the necessary messages and procedures exist.  Specifically,
the network management messages (DAVA, DUNA, etc.) can be sent by a
relay.  The ASP, IPSP and SG can support the AMF (Address Mapping
Function) or GTT, in any form that it wishes, to determine the next hop
for SUA messages.

It is particularly important that some IPSP be able to support relay and
GTT, otherwise, each IPSP in a network would have to perform final GTT
locally, resulting in an unmanageable network.

It might help you to start with the understanding that, although common
text was shared to save redundant wordsmithing, the AS concept for SUA
is different from that for M3UA.  Just as it is different for M2UA and
IUA, etc.

--brian

Stanislav Ivanovich wrote:                       (Fri, 16 Dec 2005 23:54:37)
> 
>    Hello again,
> 
> 
> 
>    In  addition  I  would  say that GT'es are not managed (neither on the
>    SCCP  nor  on  this  SUA  interface).  Therefore  if one would somehow
>    managed  to incorporate SUA relay in the AS/RC concept then what would
>    happen  if  we  have  a  pool of IPSP processes equipped with GT relay
>    which  are  however  used  as  the 2nd (or 3rd or 4th...) stage of the
>    GT-relay?
> 
> 
> 
>    In  this  case  the  AS  concept  cannot  help  the  originating  SCCP
>    application  after  all  our efforts to incorporate SUA relay into the
>    AS/RC concept! The point is that AS redundancy model in this case does
>    not help!
> 
> 
> 
>    Redundancy  of  GT  based  relays  in my view should be covered by the
>    SG-SG  concept as well, however in this case without having conceptual
>    problems (like RC'es on the SUA-relay<->SUA-relay interface).
> 
> 
> 
>    / Stanislav Ivanovich
> 


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