Specifications

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Release Notes for Cisco 7000 Family for Cisco IOS Release 12.1 T
78-10811-05
New and Changed Information
New Hardware Features in Release 12.1(3)T
The following new hardware features are supported by the Cisco 7000 family for Cisco IOS
Release 12.1(3)T:
PA-VXB and PA-VXC
Platforms: Cisco 7200 series and Cisco 7500 series routers
The PA-VXB and the PA-VXC are multichannel packet voice port adapters that allow Cisco 7200
series, Cisco 7200 VXR, 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). This allows packet voice and packet fax calls to be placed over the
wide-area network (WAN) and sent through the gateway into the traditional circuit-switched voice
infrastructure.
The PA-VXB and the PA-VXC are single-width port adapters with two universal ports that are
configurable for either T1 or E1 connection. 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 60
medium-complexity or 120 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 network end-to-end to use it successfully. Fine-tuning your network to adequately
support Voice over IP involves a series of protocols and features geared toward quality of service (QoS).
Traffic shaping considerations must be taken into account to ensure the reliability of the voice
connection.
New Software Features in Release 12.1(2)T
The following new software features are supported by the Cisco 7000 family for Cisco IOS
Release 12.1(2)T:
AAA Server Group Deadtimer
Platforms: Cisco 7200 series routers
The AAA Server Group Deadtimer feature allows each authentication, authorization, and accounting
(AAA) server to be fully configured in the server group. Thus, you can direct AAA traffic to separate
groups of servers that have different operational characteristics.
With the introduction of this feature, deadtime has been added as a new attribute to the server group
structure. In addition, a separate timer has been attached to each server host in every server group.
Therefore, when a server is found to be unresponsive after numerous retransmissions and time-outs, the
server is assumed to be dead. The timers attached to each server host in all server groups are triggered.
In essence, the timers are checked and subsequent requests to a server (once it is assumed dead) are
directed to alternate timers, if configured. When the network access server receives a reply from the
server, it checks and stops all configured timers (if running) for that server in all server groups.
If the timer has expired, only the server to which the timer is attached is assumed to be alive. This
becomes the only server that can be tried for later AAA requests using the server groups to which the
timer belongs.