why an oganization would use ipt
trackable cost saving:
- moves, adds, and changes(MACS)
- bandwidth and equipment efficiency
- lower cost of voice transmission
- new applications and devices
phase one ip telephony migration
- keep the pbx system and digital phones
- calls routed over wan rather than pstn
- major benefit: free ld
- major requirement: quality of service
phase two ip telephony migration
- voice and data network have become one
- pbx and digital phones for sale on ebay
- true interation between voice and data
- typically new structures start here
call control models:
- distributed
- centralized
the pieces of ip telephony
- ip phone
- call agent
- vocie gateway
- h.323 mcu
- h.323 gatekeeper
- various other app server
foreign exchange connections:
- foreign exchange station(fxs)
- one port one call
- for analog devices
- generate dial tones
- foreign exchange office(fxo)
- receive dial tones
pbx connections: e+m
- ear and mouth
- receive and transmit
- earth and magneto
- trunk pbx and router