I recently quit my job at a web agency. Although some of the projects benefited people in some direct way, most it was all about optimising conversion rates and SEO stuff.
Really felt meaningless, so I quit.
SIP and RTP are a pain. Long "fixed" but still a pain. ftp still refuses to die and is a pain in active mode. There are others.
Only yesterday I had to wheel out Wireshark to prove to a telephony services provider that their bod had forgotten to update a PBX with its changed WAN address.