Mitel MiVOICE BUSINESS, Инструкция по инженерии

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Engineering Guidelines
264
However, there are additional issues, unique to wireless LANs, that must be taken into
consideration when designing a wireless LAN. These issues are best addressed by consulting
the appropriate wireless phone documentation.
Detailed information regarding SpectraLink equipment, network engineering guidelines and
numerous discussion papers can be found on the Spectralink web site. The URL is
http://support.spectralink.com/SpectralinkService/support/us/support/voice/index.html.
Additional information can be found on the Mitel On Line Web Site, under "Products and
Services", then under “Applications”, and then finally, "Wireless".
COVERAGE AND CAPACITY
The APs (SpectraLink) and the RFPs (DECT) provide the radio frequency (RF) link to the
wireless telephones, each AP or RFP will have a limitation on the number of wireless telephones
and wireless PCs that the AP/RFP can support due to site-specific issues such as RF coverage
areas, bandwidth limitations, and user expectations.
When designed correctly, the wireless LAN will ensure:
• QoS for wireless phone users
• Fair LAN access for wireless PC users
• Reliability and functionality that meet the customer's needs.
The DECT system supports roaming across subnets. This means that a DECT phone will
maintain a call in progress when the user roams into a new subnet. However, when a user
roams across subnets, the RTP packets are not carried via RF in the WLAN; the packets are
carried across the LAN.
The SpectraLink system does not support roaming across subnets. This means that a
SpectraLink phone will not maintain a call in progress when the user roams into a different
subnet. Once a user has entered a new subnet, that user will need to re-initialize the SpectraLink
phone before a call can be made.
CONNECTIVITY TO THE WIRED LAN
To ensure adequate bandwidth and to eliminate collisions, connections from SpectraLink/DECT
equipment into the wired LAN should be made with Ethernet switches rather than Ethernet hubs.
Auto-negotiation should be enabled on the Ethernet switch ports so that the Ethernet switch
can take advantage of the highest speed interfaces available on SpectraLink/DECT equipment.
Category-5 cable should be used to make the connection between the Ethernet switch and
SpectraLink/DECT equipment.
OTHER CONSIDERATIONS
Depending on the particular installation, the following issues may need to be considered:
• E-911 is not supported on wireless phones. Users should not place 911 calls from these
phones or the database entry should be entered manually to point to the default building
entrance point.