Configure ports

1. An RTMFP client connects to a Flash Media Server fmsedge process over UDP port 1935.

   Specify this port in the ADAPTOR.HOSTPORT parameter of the fms.ini file. To change this value, see Configure IP addresses and ports for RTMFP.

   Important: RTMFP and RTMP/E clients use the same port to connect to Flash Media Server. However, RTMFP clients use UDP and RTMP/E clients use TCP.

2. The fmsedge process redirects the connection to an fmscore process listening on a UDP port in the range 19350-65535.

   Each fmscore process has its own RTMFP listener. Each RTMFP listener binds to one UDP port in the range. When an fmscore process starts, the listener binds to the next available UDP port in the range specified in the Adaptor/RTMFP/Core/HostPortList/HostPort element of the Adaptor.xml configuration file. For example, if there are three fmscore processes, they listen on ports 19350, 19351, and 19352. These ports are called the RTMFP redirect ports or the RTMFP migration ports.

   The number of ports in use depends on the number of fmscore processes in use. The number of fmscore processes in use depends on how application instances are distributed. See Configure how applications are assigned to server processes.

   When the server redirects the client, it sends the client an IP address and port number. If the server is behind a NAT, specify the public IP address of the server in the public attribute of the HostPort element. The server passes this address to the client and the client uses it to connect to the fmscore process.

1. Open rootinstall/conf/_defaultRoot_/Adaptor.xml in a text editor.

2. Edit the value of the HostPort element. The default ports are as follows:

   <Adaptor> 
       ... 
       <RTMFP> 
           ... 
           <Core> 
               <HostPortList> 
                   <HostPort>:19350-65535</HostPort> 
               </HostPortList> 
           </Core> 
       </RTMFP> 
   </Adaptor>

3. If the RTMFP adaptor is behind a NAT, specify the in-front-of-NAT IP address that clients connect to in the public attribute of the HostPort element. The following example uses 12.34.56.78 for the in-front-of-NAT IP address:

   <HostPort public="12.34.56.78:19350-65535">:19350-65535</HostPort>

   To redirect the client to an fmscore process, the fmsedge process sends the client an IP address and a port number. The server knows the behind the NAT IP address, but the client can’t connect to that. The client needs to know the in-front-of NAT IP address. To tell the server its in-front-of NAT IP address, specify it in the public attribute.

4. Save the file and restart the server. See Start and stop the server

The value of the HostPort element has the following format:

<value-of-HostPort> := [<host-port-range> [; <host-port-range> [; ... ] ] ] 
<host-port-range> := [<host>][:<port-range>[, <port-range> ] ] 
<port-range> := <start-port>[ - <end-port> ] 

In this example of HostPortList, each core listens to two ports: one port from either host1:2000-2010 or host2:3000-3010 and one port from either host2:5000 or host2:3010-4000 :

<HostPortList> 
    <HostPort public="12.34.56.78:2000-2010">host1:2000-2010; host2:3000-3010</HostPort> 
    <HostPort>host2:5000; host2:3010-4000</HostPort> 
</HostPortList>

If an RTMFP adaptor is behind a NAT, specify the in-front-of-NAT IP address that clients connect to in the public attribute of the HostPort element:

<HostPort public="<in-front-of-NAT-server-IP>:19350-65535">:19350-65535</HostPort>

If you don't specify the public attribute, the server doesn’t know its in-front-of-NAT-address. The fmsedge process can redirect the client to the correct port (for example, 19351) but it tells the client the behind-NAT address, which the client can't contact.

Each HostPort element can specify a public address that corresponds to the specified port. This is the address that is advertised to clients for the given HostPort. To advertise an address, specify a value for the public attribute of the HostPort element. The public attribute has the same format as the HostPort element. The number of ports specified by the public attribute must equal the number of ports specified by the HostPort element. If the core listens on the n-th port of the HostPort value, the n-th port of the public attribute is advertised as its value.

In this example of HostPortList with a public attribute, if a core listens on host1:1005, its publicly advertised address is host2:4005.

<HostPortList> 
    <HostPort public="host2:4000-5000">host1:1000-2000</HostPort> 
</HostPortList>

NAT (network address translation) and firewall filtering can block peer-to-peer connections. In an intranet application, in which you have control over the entire network, do the following to ensure that clients can create peer-to-peer connections:

• Allow UDP traffic through any firewalls

• Use a NAT or firewall that complies with the NAT implementation recommendations of the IETF BEHAVE working group.

• Use the TURN proxy support in Flash Player to send traffic to a proxy in a DMZ that can comply with the previous recommendations. See Best practices for real-time collaboration using Flash Media Server.

In an Internet application, the application developer must choose how to handle cases in which a firewall or NAT blocks a direct peer-to-peer connection. To create an application that works for connections that aren’t peer-to-peer, create a protocol fallback to client-server RTMP and/or RTMPT. To create an application that never relays media through the server (even though some clients may not see the media), don’t create a protocol fallback.