Requirements for Connecting VoIP devices to the HEAD acoustics test network HEAD acoustics GmbH Ebertstr. 30 a D Herzogenrath

Transcription

1 Requirements for Connecting VoIP devices to the HEAD acoustics test network HEAD acoustics GmbH Ebertstr. 30 a D Herzogenrath Phone: /577 0 Fax: /577 99

2 Content 1. Introduction Network setup... 4 VoIP phones or Media Gateways connected to the LAN... 4 IAD with integrated DSL modem... 5 Cordless VoIP phones Software configuration... 7 VoIP Requirements - 2 -

3 1. Introduction To setup Voice over IP (VoIP) telephone systems can be a very complex problem. These systems very often have specific features that need special handling. In order to guarantee an efficient test setup it is necessary to check in advance of the test session if the device is able to work properly with the test equipment. This document describes the most important issues regarding the HEAD acoustics VoIP test setup. It is divided in a part for pure VoIP phones connected to the LAN, internet access devices with integrated DSL modem and VoIP cordless phones with a paired WLAN router with or without integrated DSL modem. All setups expect that network impairments shall be simulated and monitored. Therefore a NISTNet simulation is integrated. Some general information is added in a separate chapter. In order to guarantee an efficient test preparation and test setup it is highly appreciated to consider the given guidelines. In case the device under test requires different test infrastructure, pleas contact HEAD acoustics prior to the shipment of the test devices. VoIP Requirements - 3 -

4 2. Network setup VoIP phones or Media Gateways connected to the LAN If the VoIP device under test (DUT) is directly connectable to the LAN, only a few values should be configurable to ensure a flawless connection. The Network Address and the Gateway Address should be set to IP: and Gateway: The SIP Alias should be set to 100 if possible. If it is possible to dial directly to another VoIP device via IP Address, either via a configurable short dial mechanism, via the phone keyboard or a Web interface, a registrar is not necessarily needed. If a registrar is needed, the Mediatrix IP Communication Server (IPCS) is used. It is necessary to ensure that either the device is capable to deal with this server or it is able to setup and receive direct calls by using the IP address. A diagram of the test setup is plotted below. The VoIP device is marked yellow. MFE VIII ACQUA PC NISTNet Router / PC Network Route: VoIP / SIP DUT SIP-Alias: 20 IP: SIP-Server IP: IP IF1: IP IF2: SIP-Alias: 100 IP: GW: Subnet 1 Subnet 2 LAN Switch If the VoIP device is a phone, a Head and Torso Simulator (HATS) will be used to connect the phone to the measurement system. In case of a MGW, a phone simulator will be used. This phone simulator is POTS, E1 and S o capable. Therefore the MGW must provide one of these connections. VoIP Requirements - 4 -

5 IAD with integrated DSL modem If the VoIP device needs a DSL connection, the test setup will be completed by an additional DSLAM to establish a PPPoE connection. The configuration of the VoIP device and the internet access device must follow the values given in the diagram (yellow parts). The DSLAM is configured to work according to the Annex B specifications given in ITU-T G The authentication for the PPPoE connection needs a user: and password: Test05. VoIP / SIP DUT Subnet 1 DSL Router + Modem SIP-Alias: 100 IP: GW: STUN: IP int.: IP ext.: Port Forwarding TCP & UDP to SIP-DUT: - SIP Protocol - RTP Protocol PPPOE Connection DSLAM MFE VIII SIP-Alias: 20 IP: GW: Network Route: NISTNet Router / PC IP IF1: IP IF2: ACQUA PC PPPOE-Server STUN-Server SIP-Server IP int.: Only 1 network adapter! (1 x IP Address intern, 1 x IP Address PPPOE) Subnet 3 IP ext.: LAN Switch Subnet 2 Additionally a connection with encapsulated Ethernet can be established as shown in the next figure. VoIP / SIP DUT SIP-Alias: 100 IP: GW: STUN: Subnet 1 DSL Router + Modem IP int.: IP ext.: Port Forwarding TCP & UDP to SIP-DUT: - SIP Protocol - RTP Protocol Ethernet Encapsulated Connection Fixed IP+GW, no DHCP! DSLAM MFE VIII SIP-Alias: 20 IP: GW: Network Route: NISTNet Router / PC IP IF1: IP IF2: ACQUA PC PPPoE-Server STUN-Server SIP-Server IP1: Subnet 3 LAN Switch Subnet 2 VoIP Requirements - 5 -

6 It is necessary that the IAD is STUN capable. If a separate VoIP phone is used behind the DSL modem, this device must be able to change the SIP and RTP ports. The telephone simulator which is used is POTS, E1 and S 0 capable. Therefore the IAD must provide one kind of these connections. Cordless VoIP phones A cordless VoIP telephone can be realized as a DECT phone with the VoIP mechanisms in the DSL IAD or as a WLAN router VoIP phone combination. In both cases the setup must be done according to the previous chapter. Additional information about the configuration of the phone must be delivered. If the WLAN device requires a specific access point, this must be delivered with the phone. Otherwise a WLAN router provided by HEAD acoustics will be used. VoIP Requirements - 6 -

7 3. Software configuration The VoIP device shall be able to be fully controlled. That means that besides the end user web interface all other mechanisms of controlling should be known to HEAD acoustics. This might be a possibility to switch the Web interface to an expert mode, to configure the device with some parameter files via ftp or to set parameter with a terminal connection. All known issues as well as a short description of the commands and parameters should be delivered with the device. The description of the parameters should also include a description of the valid value range for each parameter. The most important parameters for testing are: the used codec (see list below) the codec packet length the size of the jitter buffer the voice activity detection the comfort noise insertion the behavior of the packet loss concealment the behavior of the echo canceller and it s control parameters possibilities of call setup without using a register server If the device shall be optimized in any aspect (e.g. the echo canceller) a detailed description of this part of the signal processing is needed, including all involved parameters and a sketch of the signal flow. Known issues in setting parameters should be communicated to HEAD acoustics. The following codecs are supported by the HEAD acoustics test setup: 10 ms 20 ms 30 ms 40 ms 50 ms 60 ms A/µ-Law G G L16 + G G VoIP Requirements - 7 -