
254 Extreme Networks Consolidated Hardware Guide
BlackDiamond 6800 Series I/O Modules
• Support for jumbo frames
• Extensive support for Quality of Service (QoS) and Differentiated Services (DiffServ), including:
— Eight ingress queues and eight egress queues per interface
— Ingress and egress rate shaping and limiting
— IEEE 802.1Q VLAN priorities
— Weighted RED (WRED) congestion avoidance algorithm
— Assured Forwarding and Expedited Forwarding RFCs
• Support for NetFlow Version 1 per-flow statistics, including:
— Capacity for two million flow records per PoS module
— Scalability via distribution to groups of flow-record collector devices
— Filters enabling statistics to be maintained for selected flows
— Aggregation option for further reducing the volume of exported data
• Resiliency with fast recovery from SONET link failures via support for Automatic Protection
Switching (APS) protocol in multiple configurations, including networks where the working and
protection lines are:
— Terminated in the same SONET module
— Terminated in different SONET modules residing in the same BlackDiamond 6800 series system
— Terminated in different SONET modules residing in different BlackDiamond 6800 series systems
• Support for service provider specific features, such as:
— Flexible remapping of DiffServ codepoints
— Flexible remapping of IEEE 802.1Q VLAN IDs
— VLAN tunneling via nested 802.1Q tags
— Port tunneling of High-Level Data Link Control (HDLC) byte streams
Function Summary
The following sections provide brief descriptions of the key functions provided by the PoS modules. For
more information on how to configure the PoS modules, see the ExtremeWare Software User Guide and
the ExtremeWare Command Reference Guide.
SONET and SDH. SONET and SDH are the two terms used to identify a time division multiplexing
technology that is optimized for transporting voice traffic across a digital optical network, but that is
also capable of providing high-speed capacity for transporting data.
The term SONET is used to identify the technology used within the North American digital network. Its
standards are published by Bellcore and the American National Standards Institute (ANSI). The term
SDH is used to identify the equivalent standard approved by the International Telecommunication
Union (ITU) for use in Europe and elsewhere in the global digital network. Because SDH evolved out of
SONET, the two standards are closely joined and have been widely accepted as a dominant choice for
implementations requiring high transport capacity and resistance to failure.
PPP. PPP encompasses a suite of protocols designed to provide standard methods for transporting
datagrams over point-to-point links. The use of PPP over SONET links is commonly referred to as
Packet over SONET, or PoS. The Extreme Networks implementation of PPP for the PoS module
provides support for the following protocols in the PPP suite:
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