| Internet Protocol Private Branch Exchange | | | | work from home, he can use the SIP software phone |
| Private Branch Exchange: | | | | and can answer calls to their extension, as used in the |
| The communication between the PSTN phones is | | | | office. Calls can be diverted to any phones by using |
| managed by the central office or the Local exchange | | | | SIP Protocol characteristics. Easier to manage |
| in a particular area. Similarly to manage the | | | | because of web/GUI based configuration interface. An |
| communication between the internal phones of the | | | | IP PBX can be managed via a web-based |
| company is Private Branch Exchange (PBX) is | | | | configuration interface or a GUI, allowing the user to |
| employed. | | | | maintain it and use it easily. Scalable Not so with an IP |
| The Single telephone line from the Exchange comes | | | | PBX: a standard computer can easily handle a large |
| into the organization, but inside the organization using | | | | number of phone lines and extensions - just add more |
| PBX these lines are divided into many sub-lines and | | | | phones to your network to expand. Quality The Signal |
| then they are given Extension numbers. | | | | quality is much more improved than a normal PSTN |
| PBXs make communication among the internal | | | | lines as this runs on the IP Address and uses digitized |
| telephones of a private organization and also connect | | | | data network. |
| them to the Public Switched telephone Network | | | | Easy to configure and Install The installation of IP PBX |
| (PSTN) via Trunk lines. | | | | is very easy. Any one who knows the basics of |
| If a person has to call another person within the same | | | | computer and networking can install this. To connect a |
| organization, the call will just be routed to the PBX and | | | | hardware phone to an IP PBX system, directly plug |
| then to the destination without going to the Local | | | | into a standard network port. Note: SIP, short for |
| Exchange. This reduces the cost of calls within the | | | | Session Initiation Protocol is an IP telephony signaling |
| organization.Private Branch Exchange | | | | protocol used to establish, modify and terminate VOIP |
| IP PBX: | | | | telephone calls. SIP was developed by the IETF. How |
| An IP PBX is a complete telephony system that | | | | Does IP PBX Works? IP phone to IP Phone Call |
| provides telephone calls over IP data networks. All | | | | connection in an IP PBX system: An IP phone |
| conversations are sent as data packets over the | | | | connects to a LAN either through a hub port or a |
| network. This is not hardware as a PBX is. This is | | | | switch port. The phone can talk with Call Manager and |
| software and even hardware is used sometimes. The | | | | registers itself. Call Manager Stores the |
| technology includes advanced communication features | | | | IP-address-to-Phone number mapping (and vice versa) |
| and provides a significant dose of worry-free | | | | in its tables. When a user wants to call another user, |
| scalability. This could enable people to make | | | | he dials the called party's phone number. The Call |
| VoIP-to-VoIP, VoIP-to-analog or analog-to-analog calls. | | | | Manager checks the SIP address of the dialed Phone |
| Infrastructure of an IP-PBX: | | | | number to find the destination. |
| An IP PBX system consists of one or more Sip or | | | | Then it resolves it into the IP address of the destination |
| VOIP Phones, an IP PBX server and optionally includes | | | | and generates an IP packet version of ring tone to the |
| a VOIP Gateway. The IP PBX server is similar to a | | | | called IP phone through the TCP connection. When the |
| proxy server. An IP PBX server may be software | | | | called IP phone receives the packet, it generates a ring |
| that is installed in the PC or the traditional PBX which is | | | | tone. Now the user receives the call, the Call Manager |
| updated as an IP PBX system. Call manager (or soft | | | | instructs the called IP phone to start talking removes |
| switch) is for call control, signaling and management | | | | itself from the loop. From now, the call is in between |
| This is connected to the data network itself. The | | | | the two IP phones. |
| Hardware based phones or soft Phones, initially | | | | When any change occurs during the call due to a |
| register with the IP PBX server. | | | | feature being pressed on one of the phones, or one of |
| When they want to communicate they request the | | | | the users hanging up, the information goes to Call |
| server for establishing the connection. The IP PBX has | | | | Manager through the control channel. PSTN to IP |
| a directory or the database of all phones or users with | | | | Phone call connection: If a call is made to a number |
| the corresponding SIP Address. When the request is | | | | outside of the IP PBX network, Call Manager routes |
| place from the IP Phone, the IP address is first | | | | the call to an analog or digital trunk gateway which in |
| resolved to the Sip Address or extension no. in the IP | | | | turn routes it to the PSTN network. The Call in the |
| PBX and then it is routed to the destination. Thus the | | | | PSTN network is routed to the appropriate phone. |
| routing of the internal calls directly and the routing of | | | | Calls from the PSTN network are also sent via the |
| the external calls through VOIP Gateway is done. | | | | analog or digital trunk gateway, and then the call is |
| Analog Station Gateway allows fax machines to be | | | | routed to the Call Manager. NOTE:- SKYPE Calls will |
| connected to IP PBX. Analog Trunk Gateway allows | | | | be directly passed to the data network and over the |
| the IP PBX to connect to the PSTN or PBX. Digital | | | | internet, and then routed to the Call Manager for the |
| Trunk Gateway supports both digital T1/E1 connectivity | | | | connection establishment. |
| to the PSTN and conferencing. | | | | IP-PBX: |
| Note:- | | | | Private Branch Exchange using VoIP Technologies |
| VOIP - Voice over Internet Protocol | | | | Featureso Unlimited Auto Attendants: This allows |
| PSTN - Public Switched Telephone Network | | | | callers to be automatically transferred to an extension |
| PBX - Private Branch Exchange | | | | Many of these offer a simple menu system ("for sales, |
| SIP - Session Initiation Protocol | | | | press 1, for service, press 2, etc., to reach a live |
| IP PBX Advantages: | | | | operator by dialing a number, for example '0').o Cell |
| IP-PBX employs converged data and voice networks. | | | | Phone Integration: When you already have a Mobile |
| This uses same data line for Internet access, as well | | | | phone for your business, the cell phone integration of |
| as VoIP communications and traditional telephone | | | | the IP PBX system will help you to continue to use it.o |
| communications, unlike the traditional PBX. Eliminate | | | | Direct Inward Dialing: This feature allocates a range of |
| vendor lock in. IP PBXs are based on the open SIP | | | | no.s all connected to their customer's PBX. The calls |
| standard. You can intercommunicate between IP | | | | from the PSTN users will directly routed to the |
| Phones, PSTN network, SIP Phones or Skype in the | | | | particular extension in the IP PBX.o Time of Day |
| internet in a IP PBX network. Cost Saving IP PBX can | | | | Routing: At certain times of the day, you may need |
| use a VOIP Service. If you have branch office, you | | | | calls to be routed to one phone number instead of |
| can easily connect phone systems between branches | | | | another. With IP PBX, you can easily set up a system |
| & make free phone calls. It has made the long | | | | that manages the calls and routes them to various |
| distance calls cost effective as it uses IP network. No | | | | extensions.o Voicemail to Email: When you are away |
| phones wiring. The phones used in IP PBX can be | | | | from home, all the voice mails will be sent to your |
| connected to the data network or the DSL line | | | | mail.o SMS Voicemail notification: Text messages to |
| itself.\the existing communication infrastructure can be | | | | alert you of new voicemails are also helpful for the |
| used. | | | | small business owner on the go.o ANI Routing: The |
| There is no need to change the phones or the Phone | | | | caller's telephone number and line type are captured |
| wiring. Hot Desking While the process of moving the | | | | by ANI equipment even if caller ID blocking is |
| desks from one place to other, traditional PBXs require | | | | activated.o Fax Support: When you need to send |
| extensions to be re-patched. With IP PBX the user | | | | faxes, you will still be able to do so with an IP PBX |
| simply can simply take his phone to his new desk. No | | | | system. With fax support, faxes can not only be sent, |
| patching required. Roaming If an employee has to | | | | but also read via the Web. |