14-8 NCAUUI
297-2521-106 Standard 23.01 March 2001
User Flow Control
User Sending Congestion Control Message with “Receiver Not
Ready”
Once the user enters a congestion state, the remote end user sends a Q.931
Congestion Control message containing Congestion Level IE set to
“Receiver Not Ready” to the DMS-250 switch. When the DMS-250 switch
receives this message, it marks the remote end user in congestion. The
switch may forward the Congestion Control message to the far-end user by
the DMS-250 switch. The DMS-250 switch serving the congested far-end
user, does not send User Information messages to the congested user until
the switch clears the user congestion. The user in a congestion state can
continue to send User Information messages to the far-end user.
User Sending Congestion Control Message with “Receiver
Ready”
Upon leaving the congestion state, the remote end user sends a Q.931
Congestion Control message containing Congestion Level IE set to
“Receiver Ready” to the DMS-250 switch. When the DMS-250 switch
receives this message, the switch marks the remote end user as
non–congested. The system may forward the Congestion Control message to
the far-end user by the DMS-250 switch.
User Receiving Congestion Control Message with “Receiver Not
Ready”
If the far-end user receives a Congestion Control message with Congestion
Level IE set to “Receiver Not Ready,” the far-end user suspends sending
User Information messages. If the far-end user, after receiving an indication
of “Receiver Not Ready,” continues to send User Information messages, the
DMS-250 switch discards these messages. The far-end user receives no
indication that the User Information messages are discarded.
User Receiving Congestion Control Message with “Receiver
Ready”
If the far-end user receives a Congestion Control message with Congestion
Level IE set to “Receiver Ready,” the far-end user can resume sending User
Information messages to the remote end user.
Network Flow Control
The DMS-250 switch uses the following algorithm to control the flow of
User Information messages:
• burst parameter X, initialized to office parameter UUS_BURST
To Next Page