3Com 3C975-F ATMLink PCI 155MB ATM Fiber MMF SC Network Interface Card

The 3C975 ATMLink NIC is available in two models: the 3C975-F and the 3C975-UTP (Figure 1). The 3C975-F NIC has an SC duplex fiber-optic cable connector for double-strand 62.5/125 µm multimode fiber-optic cable. The 3C975-UTP NIC has an RJ-45 connector and requires Category 5 unshielded twisted-pair cable. Both 3C975 ATMLink NICs are high-performance single-slot, bus master, half-length PCI cards that provide 155.52 megabit per second (Mbps) Synchronous Optical Network (SONET STS-3c) physical layer support.

The 3C975 ATMLink NICs support the following features:

• Intuitive graphical user interface (GUI) for LEC configuration and NIC diagnostic programs
• ATM Forum standard LAN Emulation Client (LEC)
• ATM Forum AAL5 ATM adaptation layer
• ATM Forum UNI 3.0/3.1 standard signaling for switched virtual circuit (SVC) connections
• Up to 4 NICs per system
• Up to 16 LAN emulation clients (LECs) per NIC
• Simultaneous token ring and Ethernet LEC operation on the same NIC
• Up to 512 active connections per NIC
• Up to 4,096 open and 1,024 simultaneously active virtual channel connections per system
• Viewable ARP table for each LEC
• Resilient Server Link capability to protect against link failure
• Compliance with PCI Local Bus Specification, revision 2.0
• Link LED to indicate connection status
• Traffic shaping (user-defined maximum peak rate per LEC)
• Interim Local Management Interface (ILMI) 3.0 service
• User-selectable virtual path identifier/virtual circuit identifier (VPI/VCI) range
• Simple Network Management Protocol (SNMP) agent for NICs operating under the Windows NT operating system

Figure 1 3C975-F and 3C975-UTP ATMLink NICs

Emulated LAN (ELAN) Overview

The 3Com ATMLink network driver conforms to the ATM Forum LAN Emulation over ATM Specification 1.0 to interoperate with legacy LAN networks. LAN emulation supports the multicast, broadcast, and address resolution services characteristic of shared media LANs, within the connection-oriented ATM environment. Four devices are defined to provide these LAN emulation services:

• LAN Emulation Client (LEC) found on all end stations
• LAN Emulation Configuration Server (LECS)
• LAN Emulation Server (LES)
• Broadcast and Unknown Server (BUS)

The 3C975 ATMLink NIC network driver provides the LAN Emulation Client and supports up to 16 LECs per NIC (Windows NT and NetWare 4.1x). Each LEC configured on an ATMLink NIC is regarded by the network operating system as a separate (emulated) NIC and receives a unique MAC address. An "emulated" NIC connects to an emulated LAN (ELAN). In short, each physical ATMLink NIC can connect to up to 16 separate ELANs.

The term ELAN is often used to denote an LEC in the 3Com ATMLink utilities, installation programs, and user guide.

An ELAN is a logical grouping of end stations within an ATM network. The ATM network administrator creates ELANs when configuring the ATM switches. Membership in an ELAN is independent of the physical location of the end station within the ATM network. An end station can belong to multiple ELANs simultaneously. Mixed-media edge devices that are connected to ATM switches enable ATM end stations to interoperate with legacy LAN end stations, because the legacy LAN end station and the ATM end station can be members of the same ELAN. This guide includes configuration procedures that allow an LEC to join an ELAN.

For more detailed information on LAN emulation and emulated LANs, access the 3Com World Wide Web site at:

http://www.3com.com/

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