3-5
Operation
FDDI Network Interface Block
The 9A426-02 Module’s FNB Interface includes an FDDI Network Interface Block
(FNIB). Canonical frames processed by the module’s SmartSwitch ASIC core that
are destined for one of the two FNBs on the SmartSwitch 9000’s backplane are
first converted by the FNIB into FDDI packets and then transmitted onto the
selected FNB. Conversely, FDDI packets received by the module from an FNB are
converted by the FNIB into canonical frames and forwarded to the SmartSwitch
ASIC core for processing.
ATM Network Interface Block
The 9A426-02 Module’s ATM Interface includes an ATM Network Interface Block
(ANIB). ATM cells that enter the module’s front panel port(s) are converted by the
module’s ANIB into canonical frames. The ANIB uses hardware (ASICs) to
perform its conversions. The canonical frames are then forwarded to the
SmartSwitch ASIC core (a separate set of ASICs on the module) for processing.
Conversely, canonical frames processed by the module’s SmartSwitch ASIC core
that are destined for front panel ATM ports are converted via ASICs in the ANIB
into fixed length (53 byte) ATM cells and then transmitted to the ports. The ANIB
uses encapsulation techniques in accordance with the ATM Forum LAN
Emulation Specification. These techniques include the capability to encapsulate
ATM data in either Ethernet or Token Ring frame formats.
SecureFast Virtual Networking
Secure Fast Virtual Networking combines the best elements of bridging and
routing technologies with connection-oriented switching. Essential to Cabletron's
SecureFast architecture is the ability to embed layer-three virtual routing services
directly into its high-performance switches. Through a simple firmware upgrade,
customers can add "intranet management" software to a broad line of Cabletron
switches, including an installed base of over one million ports.
With Cabletron's "connection-oriented" architecture, users avoid latency and
performance problems and can build intranetworks that more closely mirror the
organizational structure of their business.
Since SecureFast Virtual Networking implements the same connection-oriented
concepts as ATM, customers are guaranteed a smooth migration from packet-
based LANs to cell-based technologies. SecureFast Switching allows customers to
receive many of the benefits of ATM such as security and accountability within
LAN infrastructures.
