User guide

Overview
18 MAXCS ACM 6.5 Administration Manual
DTMF payload embedded with RTP (RFC 2833) - this feature helps to resolve DTMF
tone detection and regeneration when using G.723.1 or G.729 codecs. Low bit rate
compression can distort DTMF tones during compression and cause the far end device to
not be able to recognize the DTMF digits. RFC 2833 specifies a separate RTP payload
format to carry DTMF information to ensure the other side can recognize the tone
properly.
Dynamic Jitter Buffer - due to various delays in the IP network, audio packet streams
may be delivered late or out of order. The system is able to buffer incoming packets and
re-sequence them by maintaining a queue. This queue is adjusted dynamically to
accommodate different network environment characteristics.
Echo Cancellation - due to bandwidth limitations and device loading, long delays may
occur during packet delivery process, which worsens the echo effect voice speech. Echo
cancellation is provided to maintain reasonable voice quality.
G.711 Codec - toll quality (64K) digital voice encoding, which guarantees
interoperability and better voice quality.
G.723.1 Codec - a dual rate audio encoding standard, which provides near toll quality
performance under clean channel conditions.
G.729 A+B Codec - speech data encoding/decoding standard of 8 Kbps.
Global IP Dialing Table - The IP Dialing Table is configured in Enterprise Manager. The
IP Dialing Table configuration is used to create location-based routing in the Enterprise.
H.323 Tie-Trunk Support - Ensures backward compatibility to systems using AltiGen’s
AltiWare versions prior to 5.1.
IP Extension Auto Failover - when an IP extension is unreachable, the system will
automatically fail over to a pre-configured Mobile Extension.
IP Group Paging - allows the use of voice paging to IP phone users in a group.
NAT Configuration for SIP/H.323 - When MAXCS is behind NAT with a private IP
address, this feature helps to resolve IP address resolution problems when
communicating with an external VoIP device.
Silence Detection and Suppression - when silence suppression is enabled and silence
is detected, the system stops sending packets to the other side. The other side does not
receive any packets and plays silence.
VoIP Hop-Off Call Support - allows an extension to access a PSTN trunk on the remote
system and “hop off” to dial an outside telephone number. This hop off feature can be
enabled or disabled on the remote system. Outcall restrictions for hop off calls are
configurable.
SIP Trunk Support - MAXCS enables AltiGen’s system to connect to IP-based trunking
service providers via SIP.
SIP NAT Traversal - Allows MAXCS to connect to a remote SIP phone or IPTalk behind
NAT without changing the NAT setting at the remote location.
Support for RFC 2833 (DTMF payload embedded with RTP) - Supported in SIP
trunks only. This feature helps to resolve DTMF tone detection and regeneration when
using G.723.1 or G.729 codec. Basically low bit rate compression will distort DTMF tone
during compression. The far end device may not be able to recognize the DTMF digits.
RFC 2833 specifies a separate RTP payload format to carry DTMF information to ensure
the other side can recognize the tone properly.
Support for both SIP and H.323 Tie Trunk - When setting up a system-to-system
VoIP tie trunk, either SIP or H.323 protocol can be used.