Technical data

Features

EN4442EN00EN_0001

Siemens

● Starting the optiClient 130 on a PC from any location automatically logs off the office IP

phone (associated by the same phone number) and provides the same feature set and

class or service to the end-user as the office IP phone.

● After the remote user returns to the office, the IP phone will still be in the logged off state

and the user is prompted to start the phone. This will put the IP phone into a normal

operation mode until the IP phone is logged off again by an activation of the associated

optiClient 130.

4.6 Standby Gateways

The HG 3500 supports standby gateways that protect multiple gateways against failure. See

Section 4.15.2.2, “Standby Gateways” for more details.

4.7 Secondary Gateways

The HG 3500 supports secondary gateways that provide full redundancy to IP subscribers. See

Section 4.15.2.3, “Secondary Gateways” for more details.

4.8 Voice Compression

The HG 3500 integrated gateway supports standard G.711 encoding at 64Kbps. Compression

according to G.729 and G.723 is supported as well.

Of course the actual bandwidth requirements per connection depend on the added IP overhead

and various other settings (see Section 2.5.4, “Required Bandwidth per Connection”).

The on-board DSP module can process 60/120 channels of G.711, G.729 or G.723 encoding

including VAD, CNG and echo cancellation.

Wideband codecs according to G.722 are supported between optiPoint 410 /optiPoint 420 IP

phones. Note that the gateway itself does not terminate G.722 voice payload.

4.9 Voice Activity Detection (VAD)

Voice activity detection serves to save bandwidth in the IP network during pauses in speech.

Based on the knowledge that only one partner usually speaks at a time, while the other partner

listens, the bandwidth seized during a call is only really used in one direction (speaking station

-> listening station). In the other direction (listening station -> speaking station), only ambient

Note that the voice compression as well as the gateway functionality is performed on

DSP modules.