Configure a stand-alone IBM® Sametime® Gateway Server
to operate in a NAT (Network Address Translation) environment.
Before you begin
Traversing a NAT environment is a known issue in the SIP domain.
There are several ways to solve this issue, while some of them have
been formed as IETF standard (RPORT, STUN and ICE), others have been
formed as proprietary solutions. So what is the problem? Some of the
SIP communication parameters contain the Fully Qualified DNS Name
(FQDN) or the IP address, and the port, but a SIP device deployed
in a NAT environment does not know how it will be seen from the internet
because the NAT device translates the IP address. The SIP message
will contain IP address and port - which are not accessible
from the internet.
About this task
The stand-alone FQDN you provide must be resolvable from
the Internet so that external communities can access it. This name
must also be resolvable locally and should resolve to a local IP address.
If necessary, create an entry in the hosts file and map this name
to the local IP address. A static NAT is defined in the NAT or firewall;
the public IP address should be mapped to the stand-alone server's
internal IP address.
Procedure
- On the Sametime Gateway
server, log in to the WebSphere® Integrated
Solutions Console as the WebSphere administrator.
- Click .
- In the list of WebSphere Application
Servers, click RTCGWServer.
- In the "Container settings" section, click SIP
Container Settings and then click SIP container.
- In the "Additional Properties" section, click Custom
properties.
- Click New.
- In the Name field, enter com.ibm.ws.sip.sent.by.host.
- In the Value field, enter the fully
qualified domain name of the Sametime Gateway server.
- Click OK, and then click Save in
the "Messages" box at the beginning of the page.
- Restart the Sametime Gateway
server.