RealSystem streaming requirements

RealSystem port requirements for transparent redirection

To enable transparent proxying, you must configure the NetCache appliance, switches, or routers for RealSystem (RTSP) traffic. The recommended port numbers for transparent redirection of RealSystem traffic are as follows:

TCP port 554
UDP port 554
TCP port 80 (for HTTP encapsulation or proxying)
TCP port 8080 (for HTTP encapsulation or proxying)

Note
The preceding port list includes all ports that must be redirected for multicasting.

Firewall requirements for RealSystem streaming

The following table describes the ports that should be opened to enable TCP and UDP RealSystem streaming traffic to pass through your firewall.

Note
Although TCP port 80 is commonly used for HTTP streaming traffic, other ports, such as TCP 8080 and TCP 7070, can also be used.

Firewall location	Minimum suggested ports to open on firewall	Result if ports are not opened
Located between NetCache and the server	TCP 554 TCP 80 TCP 8080	If you do not allow TCP 554, NetCache uses TCP 80 for server-side HTTP encapsulation.
Located between NetCache and clients	TCP 554 UDP 554 TCP 80 TCP 8080	If you do not allow TCP 554, clients use TCP port 80 for client-side HTTP encapsulation.

See Streaming media protocol details for descriptions of the protocols associated with the streaming media ports.

UDP restrictions for IP spoofing for RTSP

If you enable IP spoofing for RTSP, the RealPlayer® will not be able to use UDP and will either fail over to TCP (if the player has been configured to fail over) or fail. Therefore, if you must enable IP spoofing for RTSP, ensure that the RealPlayer failover option is enabled.

IP spoofing deployments are complex, requiring a variety of planning and configuration tasks. Before you deploy IP spoofing, see the transparency chapter in the Administration Guide.

RealSystem multicasting support

RealSystem supports back-channel and scalable multicast streaming; however, NetCache 5.2 and later supports only back-channel multicast streaming.

Be aware of RealSystem proxy splitting limitations

If NetCache is placed between a RealProxy^TM and a RealSystem Server, NetCache will not split any live streams sent by the RealSystem Server. RealSystem Proxy, and OEM versions of RealSystem Proxy offered by RealNetworks' partners, use a special closed protocol to communicate with RealSystem Server. These connections use port 3030 for splitting connections and port 7802 for caching connections. Because NetCache does not listen on port 3030 or port 7802, these connections always bypass NetCache.

If RealProxy is unable to connect to the ports for these protocols, RealProxy will fail over to passthrough proxy mode for those streams accelerated by NetCache. In passthrough proxy mode, RealProxy does not offer any bandwidth savings. However, the upstream NetCache appliance will continue to perform splitting and caching.

To enable RealProxy to perform normally when accelerating a RealSystem Server (in nontransparent, reverse-proxy mode), list ports 3030 and 7802 in the Allowed Tunnel Destination Ports option (Setup tab > HTTP > Tunneling).

Note
Ports 3030 and 7802 are the default ports. You can configure RealSystem Server or RealProxy to use different port numbers for these connections.

If possible, configure the switch to redirect requests from the same client IP address to the same NetCache appliance.