[Asterisk-Dev] Security issue mumblings

[Kevin P. Fleming]

Tilghman Lesher wrote:

> In terms of SIP, the modification might be as simple as never sending
> an ACK to a 200, thereby never notifying the remote end that the
> answer is confirmed.  How that violation of the SIP spec is handled is
> obviously implementation-defined.

Bingo! The apparent situation is that some softswitches don't start the 
billing for the call until the ACK is received.