Avaya H323 ∙ Warning a Network Assessment is Mandatory, ∙ G711 20ms ∙ G723a 80ms ∙ G729 40ms

Page 16

1.8Network Assessment

WARNING: A Network Assessment is Mandatory

When installing H323 IP phones on an IP Office system, it is assumed by Avaya that a network assessment has been performed. If a support issue is escalated to Avaya, Avaya may request to see the results of the network assessment and may refuse to provide support if a suitable network assessment was not performed.

Current technology allows optimum network configurations to deliver VoIP with voice quality close to that of the public phone network. However, few networks are optimum and so care should be taken assessing the VoIP quality achievable across a customer network.

Not every network is able to carry voice transmissions. Some data networks have insufficient capacity for voice traffic or have data peaks that will impact voice traffic on occasion. In addition, the usual history of growing and developing networks by integrating products from many vendors makes it necessary to test all the network components for compatibility with VoIP traffic.

A network assessment should include a determination of the following:

A network audit to review existing equipment and evaluate its capabilities, including its ability to meet both current and planned voice and data needs.

A determination of network objectives, including the dominant traffic type, choice of technologies and setting voice quality objectives.

The assessment should leave you confident that the network will have the capacity for the foreseen data and voice traffic, and can support H323, DHCP, TFTP and jitter buffers in H323 applications.

The network assessment targets are:

Latency: Less than 180ms for good quality. Less than 80ms for toll quality.

This is the measurement of packet transfer time in one direction. The range 80ms to 180ms is generally acceptable. Note that the different audio codecs used each impose a fixed delay caused by the codec conversion as follows:

G711: 20ms.

G723a: 80ms.

G729: 40ms.

Packet Loss: Less than 3% for good quality. Less than 1% for toll quality.

Excessive packet loss will be audible as clipped words and may also cause call setup delays.

Jitter: Less than 20ms.

Jitter is a measure of the variance in the time for different packets in the same call to reach their destination. Excessive jitter will become audible as echo.

Duration: Monitor statistics once every minute for a full week.

The network assessment must include normal hours of business operation.

H323 Phone Install

Page 16

IP Office 4.2

15-601046 Issue 15b (16 July 2009)

Image 16
Contents H323 IP Telephone Installation IP OfficeH323 Phone Install IP Office Contents Page Chapter IP Office IP Phones Page IP Office IP Phones ∙ Dhcp versus Static IP Installation∙ Network Assessment What is New IP Office∙ Http User Backup and Restore ∙ IP Phone Restart using System Status Application∙ Secondary Site Specific Options Number ∙ IP500 Dhcp EnhancementsSupported Phones H323 IP Supported IP Office Core Phones Models SoftwareSystem Capacity Extension CapacityCall Capacity IP Office UnitPhone Firmware Simple Installation Complex Installation Installation Requirements ∙ Warning a Network Assessment is Mandatory Network Assessment∙ G711 20ms ∙ G723a 80ms ∙ G729 40ms Installing VCM Cards Voice CompressionIP400 VCM Cards IP500 VCM cardsPotential VoIP Problems 10 QoS232 IP With Supports Phone User PC Connection∙ Gigabit Ethernet Power Supply Options Spare Wire Power OptionsDedicated Plug-Top Power Supply Units ∙ Avaya 1151D1 Power Supply Unit PSU802.3af Power over Ethernet PoE Options ∙ Avaya 1152A1 Power Distribution Unit Mid-Span Power Unit∙ Power of Ethernet POE Switch Phone 802.3af ClassFile Server Options IP Office ManagerIP Office Unit Memory Card 3rd Party SoftwareFile Auto Generation Transferring Files to the Card Using Tftp Transferring Files to the Card Using File ManagementControl Unit Memory Card Page Chapter Installation Installation ∙ o Dhcp Mode IP Phone Software and Settings FilesDhcp Server ∙ o Number of Dhcp IP AddressesCreating/Editing the Settings File Backup/Restore Installation Creating/Editing the Settings FileManually Creating Extensions ∙ To switch to static address installation Phone ConnectionStatic Address Installation Phone Registration ∙ Password =∙ Ext. = Extension & User Setup Phone SecurityBackup Restore Http AuthenticationManual Backup/Restore Control Specifying the Bruri ValueSeries Phone Backup File Field DescriptionHttp Server Configuration for Backup/Restore Select PropertiesListing Registered Phones Error Messages Page Chapter Other Installation Options Other Installation Options VPN Remote PhonesInstallation Documentation Supported VPNremote Phone FirmwareLicensing VPNremote Phones on IP Office Product Section Title Doc ReferenceConfiguring the IP Phone for VPNremote Enable VPN Phone AllowedVlan and IP Phones Type Description Advantages DisadvantagesVlan and Dhcp Option Data Vlan Dhcp Settings Voice Vlan Dhcp SettingsDhcp Option Description Example setup Overview HP-Switch ConfigurationHP Procurve CLI output Port Vlan Description Voice DataOption Value Example System OverviewPort Vlan 209 Voice Vlan 210 Data Page Chapter Static Administration Options Static Administration Options Entering Data for Administrative OptionsHold vs Mute ∙ 4601, 4602, 5601, 5602 Speaker keyQOS Option Settings Secondary Ethernet Hub/IR Interface Enable/DisableView Details ∙ If self-test passes Self-Test Procedure∙ If self-test fails Resetting a Phone Resetting a PhoneClearing a Phone Setting the Sson on IP Office Setting the Sson on an IP PhoneSite Specific Option Number Switching automatic gain control on/off Automatic Gain Control∙ Handset AGC = ∙ Headset AGC =Chapter Restart Scenarios Restart Scenarios Correct Boot File and Application File Already Loaded Boot File Needs UpgradingNo Application File or Application File Needs Upgrading Page Chapter Infrared Dialling ∙ Dial a Number to Start a Call Infrared Dialling∙ Swap Text Files During a Call Enabling the IR Port Dialling Phone NumbersPalm Organizer Windows Pocket PCBeaming Files During a Call Chapter Alternate Dhcp Server Setup Alternate Dhcp Server Setup Using a Windows Dhcp Server Windows Dhcp Setup for H323 IP PhonesSelect Start Programs Administrative Tools Dhcp Checking for Dhcp2b. Adding a 242 Option ∙ Data type String ∙ Code2c. Adding a 176 Option Alternate Options Chapter WML Server Setup WML Server Setup What WML is SupportedTesting 4620 WML Browsing Using Xitami Installing the Web ServerConfiguring the Xitami Web Server for WAP IntroductionInstalling Sample WML Pages 4a. Creating a Simple WMLSetting the Home SET WmlportMicrosoft IIS Web Server WML Configuration Apache Web Server WML Configuration∙ Associated extension wml Open URL Entry Case 1. Input Box Followed by an Anchor TagCase 2. Input Box Followed by an a Tag Case 3. Input Box Followed by a Submit ButtonPage H323 Phone Install IP Office Issue 15b 16 July IndexAvpp Conflict END of Avaya 4620 IP Phone VCM L2QVLAN PWB SN Sson SET Dnssrvr SET Domain Tftpdir Vlanid Vlantest 47 H323 Phone Install IP Office Tel +44 1707 Fax +44