Lotus Sametime Unified Telephony provides the capability to configure call routing to gateway destinations in a manner such that calls use the least expensive path available to the enterprise network, while also ensuring acceptable voice quality. This capability was formerly known as LCR (Least Cost Routing) in legacy systems.
Although cost-effective routing functionality is an inherent part of Lotus Sametime Unified Telephony, its use is optional. Depending on an enterprise' needs:
Multiple destinations and routes may be configured as described elsewhere in this section.
A set of static routes may be configured if the enterprise does not require this functionality.
Cost-effective routing is among the Lotus Sametime Unified Telephony features that provide support for OpenExchange, which is useful for enterprises that have multiple sites and PBX (Private Branch eXchange) equipment from multiple vendors.
Comparison of price and quality
Before implementing cost-effective routing, the enterprise chooses preferred routes based on the price schedules it negotiates with its suppliers, balanced with the call quality of the various routes. These comparisons of price and quality are typically determined using off-board software the enterprise uses.
Excel spreadsheets or commercial applications which may integrate directly to the Lotus Sametime Unified Telephony billing and QoS (Quality of Service) records.
Choosing preferred routes
On the basis of these comparisons, preferred routes are chosen. These routes are then implemented on Lotus Sametime Unified Telephony, and the traffic volumes and costs monitored through reports generated from billing records.
- Gateways are defined within Lotus Sametime Unified Telephony as SIP endpoints. These endpoints are given endpoint profiles that allow them to be associated with a business group, numbering plan, and routing area.
- When a call is dialed that requires off-net routing, dialed digits are analyzed by the PAC (Prefix Access Code) table in Lotus Sametime Unified Telephony to determine the call's NoA (Nature of Address) — for example, NATIONAL or INTERNATIONAL.
- After the NOA is determined, the call is routed to the Destination Code table.
- The Destination Code table passes the call to one of the following:
If a route is not operating, a timeout may occur before Lotus Sametime Unified Telephony attempts to use the next route in the destination list. If all routes are not operating, an intercept message is played via the media server.
If a trunk is full, the call instantly uses the next route in the list.
Destinations can be prioritized and limited in access by a CoS (Class of Service) or routing area assigned to the calling party. In this way, senior executives can be permitted to overflow to more expensive routes if the low cost carrier's trunk is full, while other callers might hear an intercept announcement — for example, "All circuits are busy; please try again later."
Guidelines for Implementation and Use
Although destinations can be limited in access by a user's COS or routing area, users cannot use a COS or PIN (Personal Identification Number) to override routing configured in Lotus Sametime Unified Telephony.
If all routes are restricted to permit only emergency calling after hours, a user cannot override this in any manner.
Parent topic: Routing and Translation