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

Integrated Session Border Controller DBE Deployment Scenario

This scenario requires the SP to provide capabilities such as opening pinholes for the duration of a

conversation, and doing this without exposing the devices behind the firewall to malicious threats. In

addition, given that voice is extremely sensitive to issues such as delay, latency, and packet loss, ensuring

adequate performance is a challenge. QoS mechanisms can be implemented to ensure proper priority is

assigned to voice packets.

In this deployment scenario, multiple applications share a common link. Thus a mechanism that will

limit bandwidth available to individual applications to ensure appropriate end-to-end quality is needed.

For voice, this would involve correctly marking the packet to ensure appropriate priority, as well as

controlling the number of simultaneous calls at the network entry point. Because the SP cannot dictate

what IP phones their customers use, protocol conversion functionality is needed—especially

H.323-to-SIP conversion.

Service providers require measurement of traffic for reporting and billing purposes in this potential

scenario. Some carriers may also want to offer service level agreement (SLA) for voice, for which they

want to be able to provide their customers with the proof that these SLAs are being met.

Figure 1-4 on page 1-9 illustrates a deployment where Integrated SBC is used for VoIP interworking.

Figure 1-4 Integrated SBC Used for VoIP Interworking

Data

Center

271025

SP1

IP/MPLS Network

SP2

IP/MPLS

Network

IP IP IP

M M

IP IP IP

M M

SP3

PSTN

Managed Enterprise Unmanaged Enterprise

SBC

Residential Broadband