ocr: IPTELEPHONY UINKS IP phone user. At IPp phone user. A2 P phone user 81 IP phone usert E2 Company A's intranet Company B's intranet Prvate data Company. A'SISP company BSISP: link to branca. office internet Local network Fublic:ISP: Public SSP: Lr Home IP phone user 41 Homo IP phone user IP phore user: at tranch office Figure 2. In this configuration, two companies, aucluding pranch office and home-based users, cn communi- cate with cach other using IP zelephony. User AI as trie nost extensive capabiittes, among them the ability 10 communicale with any other user On the network. Public ISPS lin ...