Gammu is a cellular manager for mobile phones/modems. It contains libraries and functions for ringtones,logos,phonebook,SMS,etc. (used by external software), a command line version (with backup/restore) and SMS gateway (with MySQL and PostgreSQL supp
pcapsipdump is libpcap-based SIP sniffer with per-call sorting capabilities. It writes SIP/RTP sessions to disk in a same format, as "tcpdump -w", but one file per SIP session (even if there is thousands of concurrent SIP sessions).
Getting started: http://pcapsipdump.sf.net/
Phone Call Cost is a program that in the end, aims to be able to pull length of call time from a phone that displays such information and multiply it by a known rate (given to the program via the UI (or hard coded in by the end user)) and return the cost
meicd - UNIX command line run daemon that connects to Nortel Meridian MAX MEI TCP/IP ports.
Records PBX event information for use in generating reports and and tracking call flow. Simply decodes the protocol and dumps the data into flat files.
Open Source SIP Back to Back User Agent) and Billing system. Has an Embeded TCL interpreter making session control and session mediation limitless in flexibility. Useful for: Routing Engine, Calling Cards, SBC, Peering, Wholesale and more!