A firewall is a piece of hardware or software that controls which data packets either enter or leave a network. To control the flow of traffic, numbered ports in the firewall are either opened or closed to certain types of packets. The firewall typically considers the destination port, the source IP address, and the destination IP address associated with each packet. Some firewalls also look at the protocol. If the firewall is configured to accept the specified protocol through the targeted port, the packet is allowed through.
When allocating ports for Windows Media streams, open all of the UDP and TCP ports that correspond to the protocols you want to support, as shown in the following table.
If you want to use... | Then open... |
---|---|
MMST | TCP port 1755 |
MMSU | UDP port 1755, and TCP port 1755 |
RTSPT | TCP port 554 |
RTSPU | UDP port 5005, and TCP port 554 |
HTTP | TCP port 80 |
Port range restrictions potentially affect all remote procedure call (RPC) and Distributed Component Object Model (DCOM) applications sharing the system, not just Windows Media Services. If the port range is not broad enough, other services such as Internet Information Services (IIS) will fail with random errors. The port range must be able to accommodate all services in the system that use RPC, COM, and DCOM.
Note | To enable IP Multicasting you must allow packets to be sent through your firewall to this standard, Class D multicast IP address range 224.0.0.1 to 239.255.255.255. |