58 CHAPTER 2: INSTALLING SYSTEM HARDWARE COMPONENTSHow ManyTelephones orDevices Does the NBXSystem Support?The NBX 100 system accommodates 200 devices. The SuperStack 3 NBXsystem can support 1500 devices.The following items are defined as devices in the NBX system:■ Each 3Com telephone■ Each Single-port Analog Terminal Adapter (ATA)■ Each port on an Analog Terminal Card■ Each Attendant Console■ Each T1 or E1 channel■ Each B channel (if you are using ISDN BRI)■ Each Line Card port■ Each instance (installation) of the pcXset™ Soft Telephone application■ Each ConneXtions H.323 portExamples:■ With 300 3Com telephones, a SuperStack 3 NBX system canaccommodate up to 1200 additional devices, in any combination ofcard ports, Attendant Console, T1 channels, and so on.■ With 124 telephones, an NBX 100 system can have no more than 76additional devices.For detailed information on device limits, see “System ConfigurationGuidelines” on page 47.What Effect Does anNBX System Have ona LAN?A 10 Mbps Ethernet LAN can support a fully configured, fully utilizedNBX 100 system. A 100 Mbps Ethernet LAN can support a fullyconfigured, fully utilized NBX SuperStack 3 system. That is, a 10 MbpsEthernet LAN with 200 “voice devices” (3Com telephones and outsidetelephone lines) can support the toll-quality audio provided by theNBX 100 system even when all 200 devices are in use. Similarly, a100 Mpbs LAN can support toll-quality audio with a fully configuredSuperStack 3 NBX system. If you use an Ethernet switch, verify that itsupports the 802.1P and 802.1Q specifications.
