Specifications

24
Release Notes for Cisco IOS Release 12.0 S
78-7130-11 Rev. B0
New and Changed Information
Access List Performance Improvements for Cisco 12000 Gigabit Switch Routers
Platforms: Cisco 12000 series
Access list (ACL) performance improvements are provided for two types of Cisco 12000 line cards:
• Line cards using engine 1 architecture
• Line cards using engine 2 architecture
The ACL performance improvement is implemented in a slightly different way depending on the line
card type. Engine 1 line cards achieve ACLperformance improvement strictly through hardware, using
an improved ASIC design. Engine 2 line cards use a microcode enhancement in the packet switch ASIC
(PSA) for packet-over-SONET (POS) applications. See the following document for further information:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120limit/120s/120s10/h
w_acl.htm
Cisco Optical Regenerator
Platforms: Cisco 12000 series
The Cisco Optical Regenerator is a bidirectional OC-48/STM-16 regenerator that sends optical signals
over the longest distance possible. It supports single-mode long reach optical-fiber transmission when
connected to an OC-48 line card that is installed in a Cisco 12000 series Gigabit Switch Router (GSR).
The SONET specification for fiber-optic transmission defines the standard for single-mode fiber. The
regenerator provides an end-to-end IP transport for long distances by forwarding SONET/SDH traffic
at OC-48 line rates.
The Cisco Optical Regenerator uses only single-mode fiber because signals can travel farthest through
single-mode long reach fiber. The maximum distance for single-mode installations of the regenerator is
determined by the amount of light loss in the fiber path andby the physical limitation of sending optical
fiber to optical light over exceptionally long distances. High-quality single-mode fiber with minimal
high-quality splices can carry a Cisco Optical Regenerator signal up to 50 miles (80 kilometers).
Extended Ethernet Frame Size Support
Platforms: Cisco 12000 series
Cisco IOS Release 12.0 S now supports Extended Ethernet Frame Size in accordance with the Network
Working Group Internet Draft titled “Extended Ethernet Frame Size Support,”
draft-kaplan-isis-ext-eth-00.txt.