Subject: [magma] (Mldv2 ) Rfc 3810 clarifications/issues

From: Balaji Sankaran <[email-masked]>
Date: Wed, 10 Nov 2010 12:43:37 +0530

Hello,

I need a couple of clarifications in MldV2 Rfc 3810.

1)  In section 7.4,1 "Reception of Current State Records", I see the 
following operation

  EXCLUDE (X,Y)     IS_EX (A)     EXCLUDE (A-Y, Y*A) (A-X-Y)=MALI
                                                       Delete (X-A)
                                                       Delete (Y-A)
                                                       Filter Timer=MALI

Whether the src timer (A-X-Y) should be set to Filter timer instead of 
MALI.  Why we need
to set the src Timer for these srcs to MALI ?.  Setting it to MALI will 
take longer time for  these
srcs to get excluded.

Note that  TO_EXC report handling sets them to Filter timer instead of 
MALI.

EXCLUDE (X,Y)   TO_EX (A)      EXCLUDE (A-Y,Y*A)    (A-X-Y) =
                                                             Filter Timer
                                                        Delete (X-A)
                                                        Delete (Y-A)
                                                        Send Q(MA,A-Y)
                                                        Filter Timer=MALI

2)  Regarding src deletion when there is a GSSQ retransmission scheduled 
for it:

Lets take the following reports:

Report A  { M1, IS_IN (S1, S2)  }
Report B  { M1, TO_EX (S1,S2) }
Report C { M1, IS_EX ( S1,S3) }

Step 1)* Send Report A *
Router will have following information for Multicast address M1,

State -           Include
src-include-list  -  S1, S2

Step 2) *Send Report B *
After handling Report B, following will be the state information for M1

State - Exclude
Src-Req-list : S1,S2
Src-Exc-List: Empty
There will be a GSSQ packet send for S1 and S2 with Sbit Unset.
There will be another GSSQ packet scheduled for these srcs (S1 and
S2)  later at LLQT interval.

Step 3) *Send Report C* before the scheduled GSSQ for S1 and S2 is 
transmitted.
According to the state  table, Report C handling will   delete the src 
S2 (Delete
(X-A) ).

EXCLUDE (X,Y)   TO_EX (A)      EXCLUDE (A-Y,Y*A)    (A-X-Y) =
                                                             Filter Timer
                                                        Delete (X-A)
                                                        Delete (Y-A)
                                                        Send Q(MA,A-Y)
                                                        Filter Timer=MALI

However there is an GSSQ pending for the src S2.  So what we do now ?  
Delete the src S2 and cancel the
retransmission ?  Or delete the src but do not cancel the retransmission 
?. If we are not canceling the
retransmission, whether Sbit should be True for this query ?.    I 
believe we should delete the src
and this in turn should cancel the GSSQ retransmission for this src as 
well. Let me know
if anybody has any thoughts on this.

regards,
Balaji