RTP Port Allocation Does Not Obey RFC 1889 (308682)


The information in this article applies to:

  • Microsoft Internet Security and Acceleration Server 2000
This article was previously published under Q308682

SYMPTOMS

When you use NetMeeting through an Internet Security and Acceleration (ISA) server, you may encounter problems if another gatekeeper exists before the endpoint is reached. For example, you may observe that audio communications occur in one direction only.

CAUSE

When ISA server negotiates the ports for the Real Time Protocol (RTP), ISA server may decide to use a port numbered above the Real Time Control Protocol (RTCP) port. Although this port information is correctly passed over the control channel, some devices expect the port number to be below the RTCP port as defined in RFC 1889.

RESOLUTION

A fix is scheduled to be included in Service Pack 1 for Internet Security and Acceleration Server 2000.

STATUS

Microsoft has confirmed that this is a problem in Internet Security and Acceleration Server 2000.
Modification Type:MajorLast Reviewed:10/16/2002
Keywords:kbbug kbQFE KB308682
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