Cisco Systems ATA187I1ARF 用户手册

Information on how the ATA 187 complies with the IETF definition of SIP as described in RFC 2543 is 
found at the following URL:

http://www.ietf.org/rfc/rfc2543.txt

Line-echo cancellation

Echo canceller for each port

8 ms echo length

Nonlinear echo suppression (ERL > 28 dB for frequency 
= 300 to 2400 Hz)

Convergence time = 250 ms

ERLE = 10 to 20 dB

Double-talk detection

Out-of-band DTMF

RFC 2833 AVT tones for SIP

Cannot transmit RFC 2833 and in-band signalling, 
simultaneously.

Configuration

DHCP (RFC 2131)

Web configuration via built-in Web server

Touch-tone phone keypad configuration with voice prompt

Basic boot configuration (RFC 1350 TFTP Profiling)

Dial plan configuration

Cisco Discovery Protocol

Quality of Service

Class-of-service (CoS) bit-tagging (802.1P)

Type-of-service (ToS) bit-tagging

Does not support CoS service.

Security

RC4 encryption for TFTP configuration files

Voice coder-decoders (codecs)

G.729, G.729A, G.729AB

G.711A-law

G.711µ-law

Voice features

Voice activity detection (VAD)

Comfort noise generation (CNG)

Dynamic jitter buffer (adaptive)

Voice-over-IP (VoIP) protocols

SIP (RFC 3261 bis)