The value of tmnxMsdpMsgRcvRateThd specifies the number of
MSDP messages that can be processed before tmnxMsdpMsgRcvRate is
set. This is useful during system startup and initialization.
By default, no MSDP messages are read from the TCP session
and this is specified by the value 0.
Once the number of MSDP packets defined in tmnxMsdpMsgRcvRateThd
have been processed the rate of all other MSDP packets is rate
limited by no longer accepting messages from the TCP session until
tmnxMsdpMsgRcvRateTime seconds have elapsed.