Flow Control Using ICMP for IPv4 (Windows CE 5.0)
If a host is sending datagrams to another host at a rate that is saturating the routers or the links between them, the sending host may receive an ICMP Source Quench message asking it to slow down. The TCP/IP stack in a Windows CE-based device honors a Source Quench message provided that the message contains the header fragment of one of the device's own datagrams from an active TCP connection. If a Windows CE-based device is being used as a router and it is unable to forward datagrams at the rate they are arriving, it drops any datagrams that cannot be buffered but does not send ICMP Source Quench messages to the sender(s).
See Also
Maintaining Route Tables for IPv4
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