I have a feeling that I'm doing something wrong. I'm trying to query a SIP device on udp/5060 using netcat. You should be able to send it banners, similar to http ones, and get responses from the device.

When I send it a banner, it does absolutely nothing. Usually with http, if you press enter after you send it the string, you get a response. But with this, nothing. For kicks, I also tried to use netcat with a ntp server and see if I get a response. I *think* if you connect to it and press enter, it should return the time and date. But nada.

I have a feeling that because UDP is connectionless and TCP is connection orientated, you might have to do something special in order to receive a response. If anybody has any ideas, help is greatly appreciated.