1.2.1. OpenSER Modules

The following modules must be loaded before this module:

• No dependencies on other OpenSER modules.

1.2.2. External Libraries or Applications

The following libraries or applications must be installed before running OpenSER with this module loaded:

• None.

1.3.1. max_limit (integer)

Set an upper limit for the max-forward value in the outgoing requests. If the header is present, the decremented value is not allowed to exceed this max_limits - if it does, the header value will by decreased to "max_limit".

The range of values stretches from 1 to 256, which is the maximum MAX-FORWARDS value allowed by RFC 3261.

Default value is "256".

...
modparam("maxfwd", "max_limit", 32)
...

1.4.1. mf_process_maxfwd_header(max_value)

If no Max-Forward header is present in the received request, a header will be added having the original value equal with "max_value". An OK code is returned by the function.

If a Max-Forward header is already present, its value will be decremented. If after this operation its value will be positive non-zero, an OK code will be returned. Otherwise (for a zero value) an error code will be returned. Note that an error code will be also returned if the SIP message couldn't be parsed or if the Max-Forward header's body invalid (non numerical string or negative numerical value).

Meaning of the parameters is as follows:

• max_value - Value to be added if there is no Max-Forwards header field in the message.

This function can be used from REQUEST_ROUTE.

...
# initial sanity checks -- messages with
# max_forwards==0, or excessively long requests
if (!mf_process_maxfwd_header("10")) {
	sl_send_reply("483","Too Many Hops");
	break;
};
...