IP Based PABX - Module 2 (Gateway)

Abstract

In medium and large sca le organi za ti ons, peop le arc not loca ted \e ry close to eac h other. In th eir day to day wo rking, they need to communi ca te \\ith e,lch other both 101' th e j1mj1ose 01' hm'ing vo ice cOl11mullic;lti () n ,IS \\L' II ,IS "ll!" lr,l11 sll:rrilll; hllsiness rel,lled inCormati on in di gital rorm . As a result. t\\O lypes 0 1' netwo rk arc in CO l11mon lIsage namc ly, locali zed telephoni c net\\ ork connec ted \vith loca l e,(c hange I"or vOIce communi cati on. i.e: PABX (Pri vate Automatcd Branch eXchange) and a LAN (Loca l Area Ne twork) or computers Cor interchanging di gital inrormati on. The LAN mi ght be co nnec ted with the Internet using IP (Intern et Prolocol). To cut do wll the cost. one 01" the soluti ons is to provide vo ice communi ca ti on o\"Cr th e e:'\ isting LAN, i. e: to pro vide the functi onality ofa PABX ove r the ex isting LAN using IP. :'\ tin g PABX needs sepma te locali zed telephoni c net\\'ork, cost ove rh ead, dedicated tel ephone sets and no database support to store voice calls and uscI' inlo rmation. IP based PABX, handl es both incoming and outgo in g ca lls. It responses an incoming ca ll by ac ti vating an IVR (Interactive Vo ice Response) by pla ying an audio ril e whi ch spec i I"ie s th e extensions (short code numbers) 01" the LA N lIse rs. The system ge ts ex tcnsion entered by the PSTN cli ent and then routes th e ca ll to lhe concerned LAN cli ent (also called 11 323 Terminal). On ca ll termination, it stores call and use r informati on in a database . The product is deve loped in a modular way by a team 01" 3 students, with particu lar emphasis on three basic mod ul es. hrst modul e is 'G o/e mf)" ' whi ch handles both incoming and outgo ing ca lls. Seco ndmod ulc is '/ VR & OAj\f' whi ch interac ts with PSTN caller and find s the LAN user login status. Third modul e is 'f-I.323 Terl7lil1((/' whi ch is cli ent side appli cation. It provides ilit y or rece i\'ing incoming ca ll and mak ing outgo in g call on LAN.