Port Adapter Overview
The PA-VXA-1TE1-30+(=) (see
DSPs. This PA-VXA can support up to 32 simultaneous medium-complexity codec (G.729a, G.726, or
G.711) voice channels—enough channels to support a single T1 or E1 line.
Figure 1-2
The PA-VXAs are single-width port adapters with one universal port that is configurable for either a T1
or E1 connection. Using a PA-VXA packet voice port adapter, Cisco 7200 series routers, Cisco 7200
VXR routers, and Cisco 7500 series routers can become dedicated packet voice hubs or packet voice
gateways that connect to both private branch exchanges (PBXs) and the Public Switched Telephone
Network (PSTN). The result is that packet voice and packet fax calls can be placed over the wide-area
network (WAN) and sent through the gateway into a traditional circuit-switched voice infrastructure.
The PA-VXB and the PA-VXC (see
adapters that allow Cisco 7200 series routers, Cisco 7200 VXR routers, Cisco 7301 routers,
Cisco 7401ASR routers, and Cisco 7500 series routers to become dedicated packet voice hubs or packet
voice gateways that connect to both private branch exchanges (PBXs) and the Public Switched
Telephone Network (PSTN). With this technology, packet voice and packet fax calls can be placed over
the wide-area network (WAN) and sent through the gateway into the traditional circuit-switched voice
infrastructure.
Figure 1-3
Figure 1-4
The PA-VXB and PA-VXC are single-width port adapters with two universal ports that are configurable
for either T1 or E1 connections. The PA-VXB contains 12 high-performance digital signal processors
(DSPs) that support up to 48 medium-complexity or 24 high-complexity channels of compressed voice.
The PA-VXC contains 30 high-performance DSPs that support up to 120 medium-complexity or 60
high-complexity channels of compressed voice.
In Voice over IP, the DSP segments the voice signal into frames, which are then coupled in groups of two
and stored in voice packets. These voice packets are transported using IP in compliance with ITU-T
specification H.323. Because Voice over IP is a delay-sensitive application, you must have a
well-engineered end-to-end network to use it successfully. Fine-tuning your network to adequately
T1/E1 Digital Voice Port Adapter Installation and Configruation
1-2
Figure
PA-VXA-1TE1-30+ Port Adapter
PA-VXB-2TE1 Port Adapter
0
PA-VXC-2TE1 Port Adapter
0
1-2) is a single port T1/E1 voice port adapter with eight active
Figure 1-3
and
Figure
1-4) are multichannel packet voice port
Chapter 1
PA-VXA-1TE1-30 +
2T1/E1 VXB
1
2T1/E1 VXC
1
Overview
OL-3592-02