372 Remote Office 9150Network engineering guidelines Standard 1.0OverviewIntroductionTraditionally, Meridian 1 networks depended on voice services such as LEC andIXC private lines.Note: For the sake of abbreviation, the term “voice services” also includes faxservices.With Remote Office technology, the Meridian 1 can select a new deliverymechanism, one that uses packet-switching over a data network or corporateintranet. The role of the Remote Office node is to convert steady-stream digitalvoice into fixed-length IP packets. The IP packets are transported across the IPdata network with a low latency that varies with strict limits.HistoryIn the data world in the late 1960s, IP evolved from a protocol that allowedmulti-vendor hosts to communicate. The protocol adopted packet switchingtechnology, providing bandwidth efficiency for bursty data traffic that cantolerate high latency and jitter (variation in latency). Since IP supported the TCPtransport layer, which provided connection-oriented and reliable transport, IPtook on the properties of being connectionless and a best-effort deliverymechanism.Present dayNow, there are new considerations when the same corporate network is expectedto deliver voice traffic. The intranet introduces impairments, delay, delayvariation, and data packet loss, at levels that are higher than those delivered byvoice networks. Delay between talker and listener changes the dynamics andreduces the efficiency of conversations, while delay variation and packet errorscause glitches in conversation.Connection of the Remote Office nodes to the corporate intranet withoutpreliminary assessments can result in unacceptable degradation in the voiceservice. Instead, you must consider correct design procedures and principles.
