Polycom E340, H340, I640 manual NetLink Wireless Telephone Overview, SpectraLink Voice Priority SVP

SpectraLink Corporation	Configuration and Administration–NetLink e340/h340/ i640 Wireless Telephone
	NetLink Telephony Gateway and SpectraLink Radio Protocol

2.NetLink Wireless Telephone Overview

The NetLink e340, h340 and i640 Wireless Telephones are mobile handsets for workplace telephone systems. The handset operates over an 802.11b wireless Ethernet LAN providing users a wireless voice over IP (VoIP) extension. By seamlessly integrating with the NetLink Telephony Gateway and the site PBX, handset users are provided with high-quality mobile voice communications throughout the workplace. The handset gives users the freedom to roam throughout the workplace while providing all the features and functionality of a desk phone.

The handsets reside on the wireless LAN with other wireless devices using direct sequence (DS) spread spectrum radio technology. The handset radio transmits and receives packets at up to 11 Mb/s.

All SpectraLink products use our LinkPlus digital integration technology to integrate with various digital switch platforms. Using LinkPlus technology, handsets emulate digital telephone sets to deliver advanced capabilities such as multiple line appearances and LCD display features. See the LinkPlus Interface Guide for your PBX for information about mapping the PBX features to the handset.

2.1SpectraLink Voice Priority (SVP)

SVP is the SpectraLink quality of service (QoS) mechanism that is implemented in the handset and AP to enhance voice quality over the wireless network. SVP gives preference to voice packets over data packets on the wireless medium, increasing the probability that all voice packets are transmitted efficiently and with minimum or no delay. SVP is fully compatible with the IEEE 802.11b standards.

2.2QoS and Security

The NetLink SVP Server is an Ethernet LAN device that works with the AP to provide QoS on the wireless LAN. Voice packets to and from the handsets are intercepted by the NetLink SVP Server and encapsulated for prioritization as they are routed to and from an IP telephony server or gateway. See SpectraLink 8000 SVP Server: Administration Guide for SRP for detailed information about this device.

NetLink Wireless Telephones support basic Wi-Fi Multimedia (WMM) as part of the 802.11e protocol. If the AP supports WMM, the handset automatically discovers and uses it. WMM does not replace the NetLink SVP Server as described in the following paragraph. WMM settings must be configured on the NetLink Telephony Gateway and on the NetLink SVP Server.

When the system employs four or fewer NetLink Telephony Gateways and no NetLink SVP Server, the NetLink Telephony Gateways provide SpectraLink Voice Priority (SVP). SVP is required for handling voice packets on an 802.11 WLAN. In this configuration the handsets are limited to a maximum of 2 Mb/s. If the 11 Mb/s transmission rate is desired, a NetLink SVP Server must be added to the system. Note that if any 2 Mb/s NetLink handsets are in use (PTB500’s) the NetLink e340/h340/i640 Wireless Telephones will automatically limit speed to 2 Mb/s to maintain compatibility.

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