Operation Manual

Getting Started
Feature Overview
Cisco SPA100 Series Administration Guide 4
1
• Modem and Fax Pass-Through
- Modem pass-through mode can be triggered by predialing the Vertical Service
Activation Code for the Modem Line Toggle Code. You can configure this setting
in the Vertical Service Activation Codes section of the Regional page.
- FAX pass-through mode is triggered by the detection of a CED/CNG tone or an
NSE event.
- Echo canceller is automatically disabled for Modem passthrough mode.
- Echo canceller is disabled for FAX pass-through if the parameter FAX Disable
ECAN (Line 1 or 2 tab) is set to “yes” for that line (in that case FAX pass-through
is the same as Modem pass-through)
- Call waiting and silence suppression are automatically disabled for both FAX and
Modem pass-through. In addition, out-of-band DTMF transmission is disabled
during modem or fax passthrough.
• Adaptive Jitter Buffer
The ATA can buffer incoming voice packets to minimize the impact of variable
network delays. This process is known as jitter buffering. The size of the jitter buffer
adjusts to changing network conditions. The ATA has a Network Jitter Level control
setting for each line of service. The jitter level determines how aggressively the ATA
tries to shrink the jitter buffer over time to achieve a lower overall delay. If the jitter
level is higher, it shrinks more gradually. If jitter level is lower, it shrinks more quickly.
You can use the default settings or configure this feature in the Network Settings
section of the Line 1 and Line 2 Settings (PHONE 1 and PHONE 2) page.
• Adjustable Audio Frames Per Packet
This feature allows the user to set the number of audio frames contained in one RTP
packet. Packets can be adjusted to contain from 1–10 audio frames. Increasing the
number of packets decreases the bandwidth utilized, but it also increases delay and
may affect voice quality. You can configure this setting in the RTP Parameters section
of the SIP page.
• DTMF Relay
The ATA may relay DTMF digits as out-of-band events to preserve the fidelity of the
digits. This can enhance the reliability of DTMF transmission required by many IVR
applications such as dial-up banking and airline information. You can configure this
setting in the RTP Parameters section of the SIP page.
• Call Progress Tones
The ATA has configurable call progress tones. Call progress tones are generated
locally on the ATA so that an end user is advised of status (such as ringback)
Parameters for each type of tone (for instance a dial tone played back to an end user)
may include frequency and amplitude of each component, and cadence information.