ASPSM and ASPTM example for SG having multiple SGPs

Hi,

As everyone agrees there is a requirement for a document having test
cases or examples addressing how AS is handled by an SG (multiple
SGPs) .

Here is a proposal for such kind of example, if it is acceptable, then
we can prepare similar examples for more scenarios


5.1.5 Single ASP in an Application Server ("1+0" sparing), Two SGPs in an SG

   This scenario shows the example M3UA message flows for the
   establishment of traffic between SGPs and an ASP where only one ASP
   is configured within an AS (no backup). Both SGPs are part of an SG and
   they co-ordinate AS state between them.

         SGP2                     SGP1                     ASP1
          |                        |                        |
          |                        |<--------ASP Up---------|
          |                        |-------ASP Up Ack------>|
          |                        |                        |
          |                        |--NOTIFY(AS-INACTIVE)-->|
          |                        |                        |
          |<--------------------------ASP Up----------------|
          |--------------------------ASP Up Ack------------>|
          |                        |                        |
          |------------------------NOTIFY(AS-INACTIVE)----->|     1*
          |                        |                        |
          |                        |                        |
          |                        |<-------ASP Active------|
          |                        |------ASP Active Ack--->|
          |                        |                        |
          |                        |---NOTIFY(AS-ACTIVE)--->|
          |------------------------NOTIFY(AS-ACTIVE)------->|     2*
          |                        |                        |
          |                        |                        |
          |<--------------------------ASP Active------------|
          |--------------------------ASP Active Ack-------->|
          |                        |                        |
          |                        |                        |     3*

1* - Duplicate Notify, may not be issued by SGP
2* - Duplicate Notify, may not be issued by SGP
3* - Here Notify may be issued by SGP


5.3.2 Withdrawal of ASP, Two SGPs in an SG

   Following on from the example in Section 5.1.5, and ASP1 withdraws
   from service:

         SGP2                     SGP1                     ASP1
          |                        |                        |
          |                        |<-----ASP Inactive------|
          |                        |----ASP Inactive Ack--->|
          |                        |                        |
          |                        |                        |     1*
          |                        |                        |
          |<--------------------------ASP Inactive----------|
          |--------------------------ASP Inactive Ack------>|
          |                        |                        |
          |                        |--NOTIFY(AS-PENDING)--->|
          |                        |                        |
          |------------------------NOTIFY(AS-PENDING)------>|     2*
          |                        |                        |
          |                        |--NOTIFY(AS-INACTIVE)-->|
          |                        |                        |
          |------------------------NOTIFY(AS-INACTIVE)----->|     3*
          |                        |                        |
          |                        |                        |
          |                        |<-------ASP Down--------|
          |                        |------ASP Down Ack----->|
          |                        |                        |
          |                        |                        |
          |<--------------------------ASP Down--------------|
          |--------------------------ASP Down Ack---------->|
          |                        |                        |
          |                        |                        |

   1* - AS state will not change, as it is still ACTIVE with another SGP
   2* - Duplicate Notify, may not be issued by SGP
   3* - Duplicate Notify, may not be issued by SGP

   Note: If the SGP M3UA layer detects the loss of the M3UA peer (e.g.,
   M3UA heartbeat loss or detection of SCTP failure), the initial ASP
   Inactive message exchange (i.e., SGP to ASP1) would not occur.

It is very important from interoperability point of view, ASP
behaviour will also change with  decision of doing ASPSM and NOTIFY
procedures per SG or per SGP.

Thanks,
Sandeep