Network Router User Manual

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Cisco IOS XE Integrated Session Border Controller Configuration Guide for the Cisco ASR 1000 Series Aggregation Services Routers

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Chapter 1 Integrated Session Border Controller for the Cisco ASR 1000 Series Routers Overview

General Overview

The SBC functions break down into two logically distinct areas, as follows:

• The signaling border element (SBE) function. SBEs may support functions that include

interworking between various signaling protocols such as H.323 and Session Initiation Protocol

(SIP), call admission control, advanced routing policy management, network attack detection, or

call billing using RADIUS or DIAMETER. As part of the call admission control function, an SBE

informs the data border element (DBE) of the various quality of service (QoS) and Network Address

and Port Translation (NAPT) requirements for the call. An SBE typically controls one or more

media gateways.

An SBE may be known as a media gateway controller (MGC).

• The data border element (DBE) controls access of media packets to the network, provides

differentiated services and quality of service (QoS) for different media streams, and prevents service

theft. The DBE consists of a set of data path functions and responds to the requests made by the SBE

to open pinholes, taking into account the specified Network Address Translation (NAT)/firewall

traversal and QoS requirements.

The Integrated Session Border Controller implements the DBE function on the Cisco ASR 1000 Series

Aggregation Services Routers. A table of DBE supported features is listed in

Table 1-1 on page 1-4.

Figure 1-1 shows an example SBE/DBE architecture; your SBC architecture may differ.

Figure 1-1 Example of SBC High Level Architecture

Distributed and Unified Models

The SBC can operate in two modes or models—unified and distributed.

• In the unified model, both the SBE and DBE logical entities co-exist on the same network element.

• In the distributed model, the SBE and the DBE entities reside on different network elements.

Logically, each of the SBE entities could control multiple DBE elements. The DBE is controlled by

one SBE at any one time.

Signaling Border Element

(SBE)

Data Border Element

(DBE)

H.323 SIP Policy HA

280018

AAA CDR VPN control

QoSNAPT

PolicyRTP

H.248 interface