Polycom SpectraLink NetLink 72-1065-09 - Manual (Page 7)

SpectraLink Corporation Configuration and Administration–NetLink e340/h340/ i640 Wireless Telephone
NetLink Telephony Gateway and SpectraLink Radio Protocol
PN: 72-1065-09-K.doc Page 7
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.
2.1 SpectraLink 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.
2.2 QoS 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.