Snom 4S manual Preparing Recovery, General Outound Proxy

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messages are written, a log level of 9 means that all possible log mes- sages are written.

If the Log Filename is set, all log messages are also written to the indicated file. If the file name contains a dollar character, the dollar will be replaced with the current date. Using this method, the NAT Filter will write a log file for every day. This way you can keep a certain history of log files and remove them from the file system as soon as you think the information contained there is not relevant any more.

The Log Length number indicates how many log entries the NAT Filter should keep in internal memory. The NAT Filter writes log mes- sages using the first-in-first-out principle, so that there is no memory leak caused by log messages. The log messages written to the log file are not affected by this setting.

4.3.2 Preparing Recovery

You should specify a file name, so that the NAT Filter can Save Registrations to File. The filter will append an XML line for each reg- istration that is being refreshed to a file that has the same name as the registration file appended with a tilde symbol (for example, if you specify “regs.xml”, it will write it to “regs.xml~”). After the Registration Log- ging Time (see in timeout handling below, in seconds) the filter will move the tilde file to the main file. When the server is restarted it will read both files and this way restore the registration status on the filter. This allows the continuation of the service without waiting for the user agents to re- register. This interval should be longer than the maximum time that you give user agents for reregistration.

4.3.3 General Outound Proxy

The Outbound Proxy indicates where messages that are not coming from a UA behind NAT should be sent. Typically, this is the address of the proxy handling the traffic for the domain the NAT Filter is respon- sible for.

The outbound proxy is a SIP URI, which means it has the format sip:host. If the host contains a number behind a semicolon (as in “sip: proxy.com:5060”, for example), the NAT Filter will just do a DNS A query on the address. If not, it will follow RFC3263 (Locating SIP Servers) to find the proxy. If you use DNS SRV, you can put a server farm behind the

34 • Configuration