HP iPAQ 512 User's Guide

Voice over IP (VoIP) Application Note

HP iPAQ 500 series Voice Messenger

The goal of this document is to clearly and concisely state what HP iPAQ 500 series Voice Messenger is and is not capable of supporting for mobile IP telephony, aka VoIP, or Voice over IP. All the capabilities and interoperability scenarios haven’t been tested at this point, and until then this document will be a work-in-progress. As new information becomes available, it will be added to this document.

Contents

1 Overview..................................................................................................................... 2

2 Media and Signaling Protocols................................................................................... 3

3 Telephony Features..................................................................................................... 3

4 Audio Quality.............................................................................................................. 4

5 Hardware and Firmware ............................................................................................. 5

6 WLAN Infrastructure.................................................................................................. 6

7 IP-PBX and SIP Server Support ................................................................................. 6

7.1 Compatibility with Cisco unified Call Manager v5.1 .......................................... 7

7.2 Compatibility with Avaya Communication Manager v4.0 / SES v3.1.2 ............. 8

7.3 Compatibility with Nortel MCS 5100 v4.5.......................................................... 9

7.4 Compatibility with Nortel CS1000 v4.5 ............................................................ 10

7.5 Compatibility with Alcatel OmniPCX Enterprise v6.1...................................... 11

8 Accessory Support .................................................................................................... 12

9 Configuring VoIP...................................................................................................... 12

9.1 Enabling ‘Internet Calling’................................................................................. 12

9.2 Checking Wi-Fi.................................................................................................. 12

9.3 Using HP iPAQ Setup Assistant ........................................................................ 12

9.4 VoIP Dial Plan ................................................................................................... 14

9.4.1 IMPORTANT NOTE ABOUT EMERGENCY CALLING ...................... 14

9.5 ADDITIONAL CONFIGURATION................................................................. 16

10 Appendix A – Standards Support ............................................................................. 17

10.1 Signaling Standards Implemented.................................................................. 17

10.2 Media/Other Standards................................................................................... 18

10.3 Standards Not Implemented ........................................................................... 18

1 Overview

Mobile IP telephony services can be separated into three broad categories, each with its own specific target markets and technologies used. These categories are illustrated below:

Tested use cases for the built-in VoIP client on the HP iPAQ 500 series smartphone cover the enterprise VoIP segment exclusively and expect the enterprise has IT staff that manage their own IP-PBX systems and provision devices for enterprise users. Mobile enterprise VoIP services should be accessible anywhere the VoIP-enabled enterprise wireless local area network (WLAN) provides coverage, typically within company buildings and possibly around corporate campuses. Using the built-in VoIP client for mobile access to the company’s IP-PBX from remote locations (homes, hotels, Internet hotspots, etc.) is not a supported capability.

HP uses the native Microsoft SIP (Session Initiation Protocol) client in Windows Mobile 6 to access VoIP services, and this SIP client’s capabilities and limitations have been further split into the following categories for the purposes of this document:

 Media and Signaling Protocols  Telephony Features

 Audio Quality  Hardware and Firmware  WLAN Infrastructure  IP-PBX and SIP Server Support  Accessory Support

While Internet voice services delivered by Internet Telephony Service Providers (ITSPs) may also be based on SIP, HP has done no testing or validation of interoperability with these services at this time.

2 Media and Signaling Protocols

This category is related to the industry protocols that exist today for carrying control messages and media messages.

Supported:

 SIP – Session Initiation Protocol for Signaling [RFC 3261]  G.711 – Audio codec for compression/decompression of voice. Both A-law and

u-law variants are included.

Not Supported:

 H.323 – signaling protocol used in some IP-PBXs  SCCP – Cisco’s proprietary call control protocol for Unified CallManager.  G.729 – Compressed audio codec more suitable for voice over WLAN compared

to G.711

 Secure RTP [SRTP] – secure version of the RTP protocol [RFC 3711]

A full list of the standards supported and not supported is included in Appendix A of this document.

3 Telephony Features

This category is related to the standard telephony features available in a VoIP implementation.

Supported:

 Originate and Terminate Calls  Caller ID  Call Waiting  Call Hold  Call Mute  Call Forwarding *only with a SIM card present

o The number the call is forwarded to must be in a format [E.164] that can

be validated on the GSM network.

 Configuring Caller ID *only with a SIM card present  Configuring Call Waiting *only with a SIM card present  Call Barring *only with a SIM card present  Blind Transfer  In-Band and out-of-band DTMF

o Out-of-band DTMF is requested by default. If the other end-point

declines, in-band DTMF is used.

 Emergency Calling (over GSM only)

Interoperability testing with SIP-enabled IP PBX systems is being done to confirm feature functionality with each vendor’s SIP implementation. Refer to subsequent sections of this document for test results.

Not Supported:

 Conferencing a second line  Consultative Transfer  Call Park/Pick-up  ‘Do Not Disturb’  Emergency Calling over IP

A full list of the RFCs supported and not supported is included in Appendix A of this document.

4 Audio Quality

This category is related to the components that need to be in the device to handle audio quality.

Supported:

 Automatic Gain Control

 Adaptive Jitter Buffer Management  Voice Activity Detection  Silence Suppression  Comfort Noise Generation  Acoustic Echo Cancellation (3rdparty sourced, not provided by Microsoft)

5 Hardware and Firmware

This category is related to WLAN and other hardware/firmware components in the handset that are critical to the performance and usability of VoIP.

Supported:

 802.11b/g  802.11i (PEAPv0 and EAP-TLS with certificates)  Encryption suites: WEP64, WEP128, TKIP and AES CCMP

Not Supported:

 Full 802.1X Supplicant – Microsoft provides the limited set of EAP

authentication noted above. Additional EAP methods may be required by some customers.

*A 3rdparty supplicant is currently under consideration for a future release

 Fast Roaming – A basic roaming agent has been implemented, and specific

roaming performance results will be published when they become available.

802.11r “Fast Roaming” is currently unsupported.

*Fast roaming enhancements are under consideration for a future release

 Cisco Compatible Extensions (CCX) – The WLAN module firmware and driver

would have to be updated to support the CCX v4 ASD feature set.

*A CCX v4 implementation is currently under consideration for a future release

 Certain features of 802.11e [WMM] are not currently supported.

o Automatic Power Save Delivery (APSD) and Unscheduled Automatic

Power Save Delivery (U-APSD) power saving mechanisms are not currently supported.

o Even though packet tagging [802.1p and Diffserv] is inherently supported

by Windows Mobile 6, there may not be any benefit by tagging voice packets with a higher priority.

6 WLAN Infrastructure

This category is related to the wireless local area network (WLAN) infrastructure to which the handset connects to send and receive IP traffic. The key consideration from the mobile handset perspective is typically AP-AP roaming. Given the real time requirements of voice and the delays inherent in WLAN authentication (802.11i), the strongly recommended answer is a VoIP-enabled pervasive enterprise WLAN infrastructure. Note that HP Services has a well-developed practice for migrating customers’ WLANs to this model. The baseline requirement here is a controller-based AP deployment; not standalone APs. Examples of these controller-based WLAN product offerings include:

• Cisco Aironet APs with Wireless LAN controller(s)

• HP ProCurve Radio Ports plus Wireless Edge Services xl module(s) in 5300xl switch chassis

• Extreme Networks Altitude APs and Summit switches

• Aruba Networks APs and Mobility Controller(s)

• Meru Networks APs and Controller(s)

Testing is underway with Cisco Aironet APs and wWireless LAN controllers. Other WLAN infrastructure testing and results may be available in the future.

For optimal performance, all 802.11b and 802.11g data rates should be enabled on the APs. Limiting the data rates on the APs may prevent iPAQ 500 series devices from connecting to the AP.

7 IP-PBX and SIP Server Support

This category is related to the SIP-based IP-PBX system or server with which the handheld device must interact for VoIP services. HP testing is underway with enterprise IP-PBX products from Cisco, Avaya, Alcatel, and Nortel. Detailed test criteria and results will be added to this section as they become available.

Results of other additional testing with operator-class SIP servers (Broadsoft, Sylantro, Huawei, Alcatel, etc.) will be included when they are made available to HP.

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