VoIP concepts

  • Traditional telephone system:

PSTN public switch telephone network

Central office:

NADP: North America Dialing Plan – routing protocol

Demarc box:  outside demark box charged by telephonecompany;   inside demark box is chargedby yourself.

Trunk Lines: every single line has its ownphone number.  One trunk line only allowone call in or one call out.

Hunt group: incoming calls -- have mainnumber. If one trunk line is busy then forward to the other trunk line in thegroup.  Handled by central office.

outgoing calls:  – controlled by PBX -- can program thetelephone system outgoing call on your PBX.

The phone system:

PBX: the server that route all the calls.

Voicemail: usually separate with PBXserver.  Run all the voice stuff.

AA: Auto Attendance.  The option is programed in PBX, but the voiceis located on Voice mail box sitting on the voice system.

Stations:

Digital/analog,  digital PBX + digital station.   Analog PBX – Analog station.    Digital PBX have a couple of analog ports.

Subscribers:

Voice mail – don’t have to have a physicaltelephone,  can route directly to theirmailbox.

Ports: the ports you buy determine how manypeople you can voice mail them in one time.

  • VoIP telephone system:

VoIP servers:  (IP IPBX) – can rent or purchase.

Createextension with userID&passwd

IP trunk line:  over Ethernet.  VS normal trunk line.

VoIP client:  can use the userID&passwd to register onthe VoIP server.

hard phone ---computers looks like phones ,  can accessvia web browser.

soft phone

VoIP gateways:

Send IP phone signal to normal phoneline.

Connect different communicationinfrastructure.  Allow skype switch toSIP or normal phone line.

VoIP protocols:

SIP:  session initiated protocol.   Cisco/Polycom sip phone.

Privateprotocol

VoIP codecs

4.5kbps.at least per user.

Network latency and QoS

Latency:75ms.   <100ms.

Traditionlatecy: 45ms.

Unified communication: combine into youroutlook,  switch to voice and txtfile.

Voip server,   remote location site’s ip phones canregister to this ip-pbx server remotely!

时间: 2024-12-10 12:52:01

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