RTSP

The Real-Time Streaming Protocol (RTSP) is a multimedia streaming protocol that many vendors use. Cisco ASA supports inspection for this protocol in compliance with RFC 2326. The following are some of the applications that use RTSP:

• RealAudio
• Apple QuickTime
• RealPlayer
• Cisco IP/TV

Most RTSP applications use TCP port 554. On some rare occasions, UDP is used in the control channel.

The commonly used TCP control channel negotiates the data channels used to transmit audio and video. This is negotiated based on the transport mode specified on the client.

The following are the supported Real Data Transport (RDT) protocol transports:

• rtp/avp
• rtp/avp/udp
• x-real-rdt
• x-real-rdt/udp
• x-pn-tng/udp

Use the inspect rtsp command to enable RTSP inspection on the Cisco ASA.