REMOTE SITE SURVIVABILITY
As branches grow in size and importance, IT must provide a more fault-tolerant local telephony solution. One IT architect contacted for this story addressed the problem by adding dual T1s to a remote office. While more expensive than the capital costs of adding remote CPE, redundant access lines improve the availability of data, as well as the voice infrastructure. It's worth noting that dual-access lines don't necessarily incur twice the price of a single line. MCI's Internet Dedicated T1 Shadow service, for example, adds a dormant T1 that's only activated when the primary T1 fails. (The Shadow T1 can also be diversely routed to the site, further increasing reliability.) The service is priced at a lower rate, typically another $525 per month assuming a local loop charge of $240 and a port charge of $285. There's also a $50 installation charge. In contrast, a regular T1 usually costs $970 per month, with a $700 installation fee.
Where local survivability is critical, most organizations will opt for locating a gateway at the remote office. The gateway connects to the PSTN, the LAN, and, depending on the configuration, the incoming access line. The phones within the office register with the gateway, but all the call processing happens back at the telephony server in the main office. In the event of a data network failure, the gateway redirects calls to the PSTN, thus providing backup calling functionality.
Of course, locating additional CPE boosts equipment costs and introduces remote site management issues while delivering different degrees of telephony functionality. The most expensive approach was taken by Avaya, Nortel, and Zultys. Avaya's G350 Media Gateway, for example, comes with the S8300 Media Server, a backup telephony sever that Avaya refers to as a Local Survivable Processor (LSP). The server prices in at $5,800, about the same as Cisco's 2811 router with integrated voice capability. When the main line fails, the LSP functions as a mini-PBX, providing full telephony functionality. Nortel takes a similar approach with its Survivable Remote Gateway (SRG), as does Zultys with its MX25. However, the MX25 can't accept local voice mail or auto-attendant.
Using a gateway in the remote office can also provide improved voice quality. Avaya's G350, for example, can separate the channel carrying data between the phones (called the bearer channel) from the signaling used to set up the telephone connection. The data portion moves across the PSTN, while the signaling necessary for setting up phone calls or performing various telephony functions travels on the WAN. This split arrangement gives remote users on a poor DSL connection the voice quality of the PSTN, with access to all the telephony functions of the office phone system.
Subsea cable alternatives can provide a level of comfort for those concerned about disruptions. Realistically, they will continue to play a small, but critical role in the short term.
Maintaining existing network infrastructures often incurs huge technical debt before newer technologies are adopted over time.
Amid ongoing regional uncertainties, telecom infrastructure in the Middle East has expand to include terrestrial low-latency network infrastructure, which offers resilience and agility in navigating political complexities without relying solely on undersea networks.
