Nortel Networks NN43001-504 - Manual (Page 59)

WLAN IP Telephony Manager 2245 planning 59
industry. So to mitigate risks, you can use a firewall to block all but the
ports needed for IP Telephony. This practice becomes complex and costly
when multiplied by a number of subnets. A more cost-effective alternative
to implementing a firewall is to assign private addresses to the handsets
and let the WLAN IP Telephony Manager 2245 network address translation
(NAT) capabilities serve as a form of secure firewall to the telephony LAN
(T-LAN). Of course this is not as secure as using a traditional firewall to
secure the T-LAN.
The downside of putting all telephony devices into the same subnet is that
broadcasts are increased. Also, while security is simplified, the importance
of implementing adequate security measures increases because more
devices will be impacted in the event of a security breach.
WLAN IP Telephony Manager 2245 planning
Both the WLAN IP Telephony Manager 2245 and the WLAN Application
Telephony Gateway 2246 are connected to the Ethernet switch.
Installation requirements
The WLAN IP Telephony Manager 2245 requires a CAT5 cable connection
between its network port and the Ethernet switch. The WLAN IP Telephony
Manager 2245 can auto-negotiate to the type of port on the Ethernet switch.
It supports 10BaseT, 100BaseT, full-duplex and half-duplex port types.
Nortel recommends 100BaseT full-duplex.
Note: When multiple WLAN IP Telephony Managers 2245 are used, all
the WLAN IP Telephony Managers 2245 must use a uniform media type.
Do not use full-duplex on some and half-duplex on others, or 10BaseT
on some and 100BaseT on others.
Capacities
The WLAN IP Telephony Manager 2245 is available in three models:
• WLAN IP Telephony Manager 2245-80: Serves 500 powered-on
handsets (80 simultaneous calls).
• WLAN IP Telephony Manager 2245-20: Serves 20 powered-on
handsets.
• WLAN IP Telephony Manager 2245-10: Serves 10 powered-on
handsets.
Capacity is measured by active calls for the WLAN IP Telephony Manager
2245-80 and by powered on handsets for the WLAN IP Telephony Manager
2245-10 and the WLAN IP Telephony Manager 2245-20. The capacity
of a system that is not based on 100Base-T, full-duplex is lower. Nortel
recommends that you not use older technology equipment.
Nortel Communication Server 1000
WLAN IP Telephony Installation and Commissioning
NN43001-504 01.02 Standard
Release 5.0 15 June 2007
Copyright © 2004-2007, Nortel Networks
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