1-15
Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring Inspection for Voice and Video Protocols
RTSP Inspection
Media lcl port 6166
Media rmt IP 192.168.5.7
Media rmt port 6058
RTSP Inspection
This section describes RTSP application inspection. This section includes the following topics:
•
RTSP Inspection Overview, page 1-15
•
•
Restrictions and Limitations, page 1-16
•
Configuring an RTSP Inspection Policy Map for Additional Inspection Control, page 1-16
RTSP Inspection Overview
The RTSP inspection engine lets the ASA pass RTSP packets. RTSP is used by RealAudio,
RealNetworks, Apple QuickTime 4, RealPlayer, and Cisco IP/TV connections.
Note
For Cisco IP/TV, use RTSP TCP port 554 and TCP 8554.
RTSP applications use the well-known port 554 with TCP (rarely UDP) as a control channel. The ASA
only supports TCP, in conformity with RFC 2326. This TCP control channel is used to negotiate the data
channels that is used to transmit audio/video traffic, depending on the transport mode that is configured
on the client.
The supported RDT transports are: rtp/avp, rtp/avp/udp, x-real-rdt, x-real-rdt/udp, and x-pn-tng/udp.
The ASA parses Setup response messages with a status code of 200. If the response message is travelling
inbound, the server is outside relative to the ASA and dynamic channels need to be opened for
connections coming inbound from the server. If the response message is outbound, then the ASA does
not need to open dynamic channels.
Because RFC 2326 does not require that the client and server ports must be in the SETUP response
message, the ASA keeps state and remembers the client ports in the SETUP message. QuickTime places
the client ports in the SETUP message and then the server responds with only the server ports.
RTSP inspection supports PAT or dual-NAT. The ASA provides TCP fragment reassembly support, a
scalable parsing routine on RTSP, and security enhancements that protect RTSP traffic.
Using RealPlayer
When using RealPlayer, it is important to properly configure transport mode. For the ASA, add an
access-list
command from the server to the client or vice versa. For RealPlayer, change transport mode
by clicking
Options
>
Preferences
>
Transport
>
RTSP
Settings
.
If using TCP mode on the RealPlayer, select the
Use TCP to Connect to Server
and
Attempt to use
TCP for all content
check boxes. On the ASA, there is no need to configure the inspection engine.
Summary of Contents for 5505 - ASA Firewall Edition Bundle
Page 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Page 61: ...P A R T 1 Getting Started with the ASA ...
Page 62: ......
Page 219: ...P A R T 2 Configuring High Availability and Scalability ...
Page 220: ......
Page 403: ...P A R T 2 Configuring Interfaces ...
Page 404: ......
Page 499: ...P A R T 2 Configuring Basic Settings ...
Page 500: ......
Page 533: ...P A R T 2 Configuring Objects and Access Lists ...
Page 534: ......
Page 601: ...P A R T 2 Configuring IP Routing ...
Page 602: ......
Page 745: ...P A R T 2 Configuring Network Address Translation ...
Page 746: ......
Page 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Page 846: ......
Page 981: ...P A R T 2 Configuring Access Control ...
Page 982: ......
Page 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Page 1062: ......
Page 1093: ...P A R T 2 Configuring Application Inspection ...
Page 1094: ......
Page 1191: ...P A R T 2 Configuring Unified Communications ...
Page 1192: ......
Page 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Page 1334: ......
Page 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Page 1380: ......
Page 1475: ...P A R T 2 Configuring Modules ...
Page 1476: ......
Page 1549: ...P A R T 2 Configuring VPN ...
Page 1550: ......
Page 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Page 1966: ......
Page 2059: ...P A R T 2 System Administration ...
Page 2060: ......
Page 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Page 2099: ...P A R T 2 Reference ...
Page 2100: ......