Specifications

Cisco Unified Survivable Remote Site Telephony Feature Roadmap

Feature Roadmap

Cisco Unified Survivable Remote Site Telephony Version 4.0 System Administrator Guide

Dual-Line Mode

A new keyword that has been added to the max-dn command allows you to set IP phones to dual-line

mode. Each dual-line IP phone must have one voice port and two channels to handle two independent

calls. This mode enables call waiting, call transfer, and conference functions on a single ephone-dn

(ephone directory number). There is a maximum number of DNs available during Cisco SRST fallback.

The max-dn command affects all IP phones on a Cisco SRST router.

For configuration information, see the “Configuring Dual-Line Phones” section on page 58.

E1 R2 Signaling Support

Cisco SRST V3.0 supports E1 R2 signaling. R2 signaling is an international signaling standard that is

common to channelized E1 networks; however, there is no single signaling standard for R2. The ITU-T

Q.400-Q.490 recommendation defines R2, but a number of countries and geographic regions implement

R2 in entirely different ways. Cisco Systems addresses this challenge by supporting many localized

implementations of R2 signaling in its Cisco IOS software.

The Cisco Systems E1 R2 signaling default is ITU, which supports the following countries: Denmark,

Finland, Germany, Russia (ITU variant), Hong Kong (ITU variant), and South Africa (ITU variant). The

expression “ITU variant” means there are multiple R2 signaling types in the specified country, but Cisco

supports the ITU variant.

Cisco Systems also supports specific local variants of E1 R2 signaling in the following regions,

countries, and corporations:

• Argentina

• Australia

• Bolivia

• Brazil

• Bulgaria

• China

• Colombia

• Costa Rica

• East Europe (includes Croatia, Russia, and Slovak Republic)

• Ecuador (ITU)

• Ecuador (LME)

• Greece

• Guatemala

• Hong Kong (uses the China variant)

• Indonesia

• Israel

• Korea

• Laos

• Malaysia

• Malta