Open PCAP and Listen to UDP Port

[pksml85]

From: #494 (comment)

Could it be possible to open a PCAP file (doing EEP parsing) AND listen to a UDP port?

Looks like you can read from a file and capture HEP from a network device (p.e.: sngrep -E -I file -d device), but it doesn't allow reading from a file and starting HEP Listener mode (p.e.: sngrep -E -I file -L udp:127.0.0.1:9060). Maybe it's something not to hard to enable, but I should be discussed in another feature-request issue.

When loading a PCAP file, sngrep says it's in offline mode, even if you ask it to listen to a UDP port. I would find it very useful to be able to do EEP parsing on my PCAP file AND continue to monitor EEP messages from my PBX.

I've had sngrep open long-term and it's consuming several GB of RAM. But if I could open a PCAP file and still listen for new EEP messages, I believe it would require much less RAM and I would find it more useful and helpful.

Thanks!