Data Sheet
© 2008 Cisco Systems, Inc. All rights reserved. This document is Cisco Public Information. Page 9 of 15
Feature Description
Cisco SRST version SRST 7.0 and later are supported.
Call-control signaling H.323 Versions 1, 2, 3, and 4, Media Gateway Control Protocol (MGCP) 0.1 and 1.0, Skinny Client
Control Protocol (SCCP), and SIP call-control protocols are supported.
ITU standard voice
codecs
G.711, G.729, G.729a/b, G.723.1, G.726, and G.728, which are standards-based compression
technologies allowing transmission of voice across IP, are supported. The G.711 standard employs
64-kbps pulse code modulation (PCM) using either mu-law or a-law. Other codecs employ lower bit
rates.
Cisco Unified
Communications
Manager support
For SRST features for IP phones, refer to the SRST data sheet:
http://www.cisco.com/en/US/products/sw/voicesw/ps2169/products_data_sheets_list.html.
Cisco Unified Communications Manager support for analog and digital ports comes with Releases
6.1.3.
Telephony interface
signaling support
Cisco 880 SRST supports the following signaling protocols:
●
FXS loop-start and ground-start signaling
●
FXO
●
Inbound signaling (such as dual-tone multifrequency [DTMF] and multifrequency support)
●
BRI QSIG
Voice features
●
Echo cancellation: This feature cancels echo on tail circuits up to 64 msec (configurable tail
length).
●
Silence suppression and voice activity detection (VAD): Bandwidth is used only when someone
is speaking. During silent periods of a phone call, bandwidth is available for data traffic.
●
Comfort-noise generation: This feature reassures the phone user that the connection is being
maintained, even when no voice packets are being transmitted.
●
Caller ID support: Per-port caller ID (with per-call unblocking) is configurable over analog FXS.
●
Dial-plan mapping: This feature simplifies configuration and management through automatic
mapping of dialed phone numbers to IP addresses.
Voice port-specific
features
●
FXS: FXS provides battery polarity reversal detection and initiation for disconnect supervision
and far-end answer supervision.
●
ISDN BRI network side and phantom power: The BRI port provides the ability to connect a
private branch exchange (PBX) or private automatic branch exchange (PABX) configured as
user side directly to the router. It also provides phantom power to accommodate equipment that
requires it.
●
LED indicators show voice-processing resources and port status.
Fax and modem
●
Fax and modem pass-through allows fax and modem traffic to pass through a voice port.
●
Fax Relay provides a more robust protocol for fax transmission over packet networks. It also
supports the T.37 and T.38 fax protocols.
High-performance
flexible digital-signal-
processor (DSP)
architecture
●
Channel capacity: Cisco 880 SRST supports up to four voice channels.
●
Flexible DSP architecture: There is no need to specify codec complexity at configuration.
An appropriate codec is dynamically selected when a call is established, while allocating DSP
resources optimally.
●
Feature upgrades: The DSP architecture allows for addition of new features through simple code
updates.
System Specifications
Table 8 lists the system specifications for the Cisco 880 Series Routers.
Table 8. System Specifications
Feature Specification
Default DRAM
●
256 MB on Cisco 880 Series data models
●
512 MB on Cisco 880 Series SRST models
Maximum DRAM
●
768 MB
Default and maximum
Flash memory
●
128 MB on Cisco 880 Series data models
●
256 MB on Cisco 880 Series SRST models
WAN
●
Fast Ethernet
●
G.SHDSL (2- and 4-wire support) with ISDN backup
●
Fast Ethernet and 3G WAN for Code Division Multiple Access (CDMA) and high-speed downlink
packet access (HSDPA)
LAN switch
●
Managed 4-port 10/100BASE-T with autosensing MDI/MDX for autocrossover
