Technical Concepts; Atm (Asynchronous Transfer Mode) - Efficient Networks SpeedStream 5100 Series User Manual

SSDP
Tx Cells
Tx Errors
Tx Packets
Tx PDUs
Unicast
VC
VCI
VCMux
VPI

Technical Concepts

This section provides very brief descriptions of some of the features available on the SpeedStream Router.
AAL5 (ATM Adaption Layer 5)
AAL5 is a network layer for adapting data traffic into the format of ATM fixed-length packet
networks.

ATM (Asynchronous Transfer Mode)

ATM is a fast, cell-based technology defined by the ITU-T. It works by taking an ordinary, variable-
length data packet and segmenting it into 53-byte cells prior to transmission. The data is transmitted
over virtual channels that are designated by specific unique identifiers (virtual channel identifiers or
VCIs). There can be multiple VCIs in one virtual path. The virtual path also has a unique virtual path
identifier (VPI). Data transmitted over ATM VCs is routed by ATM switches. At the destination
node, the cells are reassembled into packets. Only one virtual path is supported on the device. In
router mode, only one virtual channel is supported. However, in bridge mode, up to 16 virtual
channels can be configured to be used as individual bridge ports.
Cloning IP Filter Rules
Defining a complete set of firewall IP filter rules can be a tedious process. To aide our SpeedStream
router users, Efficient Networks includes the capability to "clone" an existing set of rules as a starting
point in the process.
There are four preconfigured firewall levels: Low, Medium, High and ICSA-compliant. Each of these
levels has its own set of predefined firewall rules. If you want to create a set of Custom rules that are
similar to one of the preconfigured levels, you can do this through cloning. When you clone one of
the preconfigured levels, the new set of custom rules is an exact replica of the cloned level; only the
rule numbers have been changed.
When you clone a set of rules, any existing Custom rules are deleted and a new set of Custom rules (a
replica of the cloned level) is created. When you click Clone Rule Set on the Firewall – Custom IP
Simple Service Discovery Protocols
(ATM) Number of cells transmitted through the ATM layer to the wire.
(ATM) Number of SDUs that could not be transmitted due to errors.
(DSL, Ethernet, USB) Count of all encoded blocks transmitted on this channel
since router reset.
(ATM) Number of PDUs transmitted on connection.
Communication between a single sender and a single receiver across a network
Virtual Channels
Virtual Channel Identifiers
Virtual Channel Multiplexor
Virtual Path Identifiers
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