Avaya 2400 User Manual

Avaya Solution & Interoperability Test Lab

Configuring Juniper Networks J4300 and Cisco 1841 Routers to use compressed Real Time Protocol over Point-to-Point Protocol to Support an Avaya IP Telephony Infrastructure – Issue 1.0

Abstract

These Application Notes describe the steps for configuring Juniper Networks J4300 and Cisco Systems 1841 routers to use compressed RTP (cRTP) over a Point-to-Point Protocol (PPP) connection to support an Avaya IP Telephony infrastructure. The Avaya IP Telephony infrastructure consists of Avaya Media Server, Avaya Media Gateways, and Avaya IP Telephones. The Juniper Networks and Cisco routers will perform header compression for all RTP packets traversing over the PPP connection to minimize overhead and increasing available bandwidth.

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1. Introduction

RTP packets generated by Voice over IP (VoIP) telephony are typically small in size ranging in tens of bytes per packet. Various headers such as IP (20 bytes) and UDP (8 bytes) are then added onto each packet before transmission. Because of the relative small packet size of RTP packet, the IP and UDP headers compose a large percentage of overhead in each frame. For RTP packets that traverse a Wide Area Network (WAN) that has a small bandwidth, The IP and UDP headers represents an opportunity for bandwidth saving that could otherwise be used for other traffic or additional VoIP calls. The compression of RTP header is known as cRTP for short.

Figure 1, illustrate the configuration used in these Application Notes. Two separate IP networks, one in each location are connected together by a Juniper Networks J4300 and Cisco 1841 routers over a PPP connection. Each location contains an Avaya Media Server, an Avaya Media Gateway, and Avaya IP Telephones. A H.323 trunk configured between the two Avaya Media Servers running Avaya Communication Manager allows calls to be routed between the two systems. Both the Juniper Networks J4300 and Cisco 1841 routers are configured to perform RTP header compression for all RTP packets traversing over the PPP connection. Both routers are configured to prioritize VoIP traffic based on DiffServ Code Point (DSCP) information encoded in each VoIP packet. Bandwidth allocation was set on all interfaces shown to guarantee that the necessary bandwidth is reserved for VoIP traffic in the event of network congestion.

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2. Configuration

Telephones with the extension range of 3xxxx are registered with the Avaya S8300 Media Server on the right side of the figure, and telephones with extension range of 2xxxx are registered with Avaya S8500 Media Server on the left side of the figure. A uniform dial plan and an H.323 IP trunk was used to route calls between the two Avaya Media Servers. IP addresses for all the devices are statically administered.

Figure 1: Sample Network Configuration

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3. Equipment and Software Validated

The following equipment and software/firmware were used for the sample configuration:

Equipment Software/Firmware

Avaya S8300 Media Server with G350 Media Gateway Avaya S8500 Media Server Avaya Communication Manager 3.1

Avaya G650 Media Gateway -

TN2312BP IPSI HW03 FW009 TN799DP C-LAN HW01 FW015

TN2302AP IP MedPro HW18 FW108 Avaya 4602SW IP Telephone (H.323) R2.3 – Application (a02d01b2_3.bin) Avaya 4610SW IP Telephone (H.323) R2.3 – Application (a10d01b2_3.bin) Avaya 4620SW IP Telephone (H.323) R.2.3 – Application (a20d01b2_3.bin) Avaya IP Softphone 5.24.8 Juniper Networks J4300 router JUNOS 7.6R2.6 Cisco Systems 1841 router IOS 12.3(8)T6

Avaya Communication Manager 3.1

(R013x.01.0.626.0)

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4. Avaya Communication Manager

There is no unique configuration required in Avaya Communication Manager to support compressed RTP (cRTP) or any feature(s) mentioned in this document. For detailed information on the Installation, Maintenance, and Configuration of Avaya Communication Manager, please consult reference [5], [2], and [3].

Step Description

Below is the output from display ip-network-region from the SAT terminal of Avaya Communication Manager. This display shows the MEDIA PARAMETERS and DIFFSERV/TOS PARAMETERS information configured in Avaya Communication Manager.

The MEDIA PARAMETERS information will be needed in Section 5.1 Step 6 and the DIFFSERV/TOS PARAMETERS information will be in Section 5.1 Step 3 and Section 5.2 Step 2.

Note: The Call Control PHB Value of 34 is equivalent to 100010 in binary.

The Audio PHB Value of 46 is equivalent to 101110 in binary.

display ip-network-region 1 Page 1 of 19 IP NETWORK REGION Region: 1 Location: Authoritative Domain: Name: MEDIA PARAMETERS Intra-region IP-IP Direct Audio: yes Codec Set: 1 Inter-region IP-IP Direct Audio: yes UDP Port Min: 2048 IP Audio Hairpinning? n

UDP Port Max: 3029 DIFFSERV/TOS PARAMETERS RTCP Reporting Enabled? y Call Control PHB Value: 34 RTCP MONITOR SERVER PARAMETERS Audio PHB Value: 46 Use Default Server Parameters? y

Video PHB Value: 26

802.1P/Q PARAMETERS Call Control 802.1p Priority: 6 Audio 802.1p Priority: 6 Video 802.1p Priority: 5 AUDIO RESOURCE RESERVATION PARAMETERS H.323 IP ENDPOINTS RSVP Enabled? n H.323 Link Bounce Recovery? y Idle Traffic Interval (sec): 20 Keep-Alive Interval (sec): 5

Keep-Alive Count: 5

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5. Configure the Networks Routers

The following sections describe steps for configuring the Juniper Networks J4300 and Cisco Systems 1841 routers in the sample configuration.

5.1. Configure the Juniper Networks J4300 router.

This section shows the necessary steps in configuring the Juniper Networks J4300 router as shown in the sample network. The following steps use the Command Line Interface (CLI) of the J4300 router. Unless other wise specified, all routers configuration are based on Juniper Networks recommendation.

Step Description

Connect to the J4300. Log in using the appropriate Login ID and Password.

The following prompt will appears after successful log in.

interop@J4300>

Enter configuration mode by typing in edit at the prompt.

interop@J4300> edit interop@J4300#

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