KEY RELEASE MESSAGE
A new Cisco 4900 fixed configuration platform-Cisco ME-4924-10GE is introduced in this release for Broadband Aggregation. The ME-4924-10GE has 28 Gigabit Ethernet (Small Form-Factor Pluggable [SFP]) and two 10 Gigabit Ethernet (X2) wire-rate ports. This new switch is 1 RU and features 1+1 redundant internal AC or DC power supplies and a hot swappable fan tray. It will run the same images as the Catalyst 4900 Series Switch.

NEW SOFTWARE FEATURES

Trunk Port Security over EtherChannel
Trunk port security over EtherChannel® is an extension of trunk port security where redundant links from a single station are connected to a Catalyst 4500/4900 using EtherChannel. The feature enables customers to block access to the Catalyst 4500/4900 by MAC addresses other than the ones specified (or learned) on EtherChannel trunk interfaces. It preserves all the advantages of port security and EtherChannel, including redundancy and load sharing. This feature is typically deployed in data center environments with dual network interface card (NIC) servers connecting to a Catalyst 4500/4900 using EtherChannel.

Match CoS for Non-IPv4 Traffic
The match class of service (CoS) feature helps a service provider to classify packets based on CoS values while preserving its customers' packet differentiated services code point (DSCP) values inside the service provider network. The match Cos for non-IPv4 feature provides uniform class-level quality-of-service (QoS) semantics irrespective of traffic type on a dot1q-tunnel and regular trunk ports. This is typically deployed in a Q-in-Q environment, where double-tagged IPv4 packets are forwarded as non-IPV4 packets.

L2PT over Trunk
Layer 2 Protocol Tunneling (L2PT) allows customer switches to participate in L2 protocols across a service provider network. This is achieved by encapsulating Layer 2 protocol packets, such as Cisco Discovery Protocol (CDP), Spanning Tree Protocol (STP), or VLAN Trunking Protocol (VTP), before sending them across the service provider network. As a result, the customer premises equipment (CPE) switches on either side of the service provider network can continue to process the L2 protocol control packets as if they were being received from a directly connected neighboring switch. The existing implementation allowed L2PT to be used only on tunnel ports. This feature will extend the functionality so that L2PT will be available on trunk ports configured with dot1q encapsulation.

CoS Mutation
The CoS mutation feature enables Service Providers to provide differentiated services for video, voice, and data within the service provider network. In a typical L2 VPN offered by service providers, double tagged Q-in-Q traffic is forwarded with the outer tag representing the service provider's VLAN and the inner tag representing the customer's VLAN. Service providers could either retain the CoS values from the customer tag in the service provider tag or change the CoS value of the outer service provider tag based on inner customer QoS matching and classification. As a result, differentiated levels of service can be provided within the service provider network.

IP Unnumbered for SVI
IP unnumbered interface configuration enables IP processing on an interface without assigning it an explicit IP address. IP Unnumbered for SVI extends the current support for point-to-point links to switched virtual interfaces (SVIs). This feature is crucial in large service provider environments where SVIs are used to terminate L2 traffic from the CPE. This feature helps to conserve IP addresses space and simplify configuration and address management.

CISCO IOS SOFTWARE PACKAGING FOR THE CISCO CATALYST 4900 AND ME 4900 SERIES
A new Cisco IOS Software package for the Cisco Catalyst 4900 Series Switches was introduced in Cisco IOS Software Release 12.2(25)SG. It is a new foundation for features and functionality and provides consistency across all Cisco Catalyst switches. The new Cisco IOS Software release train is designated as 12.2SG.
Prior Cisco IOS Software images for the Cisco Catalyst 4900 Series, formally known as "Basic Layer 3" and "Enhanced Layer 3" images, now map to "IP Base" and "Enterprise Services," respectively. Border Gateway Protocol (BGP) is now included in the "Enterprise Services" image. Unless otherwise specified, all currently shipping Cisco Catalyst 4900 software features based on Cisco IOS Software are supported in the IP Base image of Release 12.2(31)SGA, with a few exceptions:
The IP Base image does not support any enhanced routing related features (including BGP, EIGRP, OSPF, Intermediate
System-to-Intermediate System (IS-IS) Protocol, Internetwork Packet Exchange [IPX] Protocol, AppleTalk, VRF-lite and PBR)