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Cisco IOS Software Release 15 M and T

Introduction
Developed for wide deployment in the world’s most demanding Enterprise, Access, and
Service Provider Aggregation networks, Cisco IOS Software Release 15M&T provides a
comprehensive portfolio of over 2000 capabilities, including the leading-edge functionality
and hardware support previously delivered in Releases 12.4 and 12.4T, anchored by an
intensive stability and testing program. This article will give you an overall introduction of
Cisco IOS Software Release 15M.
Release 15M&T provides:
• Broadened operational consistency for features
• Proactive support policies
• Enhanced release numbering
• Clearer software deployment and migration guidelines.
Key features of 15M&T:
• Approximately 3 new feature releases per year.
• 15 M (Extended Maintenance) releases delivered on a more frequent basis
(approximately every 16 months), enabling customers to qualify, deploy, and remain on a
release longer with active support.
• 15 T (Standard Maintenance) releases (in between 15 M releases) ideal for the very
latest features and hardware support before the next 15 M release becomes available.
• Rebuilds of 15M&T releases for bug fixes and ongoing software maintenance (no new
features delivered in rebuilds).
• Release 15.0(1)M (FCS November, 2009) is the first 15 M release.
• Release 15.1(1)T (FCS March, 2010) is the first 15 T release.
Note: AppleTalk Phase I and II, and Service Selection Gateway (SSG) feature are not
supported in Release 15M&T.

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Download the software:
Visit the Software Center on Cisco.com to download any release product
http://www.cisco.com/cisco/web/download/index.html. This site also provides valuable
Cisco IOS Software information about hardware/software compatibility, and ordering
procedures. Please ensure that you are entitled to access and download the release
through an active SMARTnet contract or purchased feature license.
Features and hardware support
Release 15M&T key innovations span multiple technology areas, including Security,
Voice, High Availability, IP Routing and Multicast, Quality of Service (QoS), IP Mobility,
Multiprotocol Label Switching (MPLS), VPNs, and Embedded Management.

Cisco IOS Packaging
Cisco IOS Packaging simplifies the image selection process by consolidating the total
number of packages and using consistent package names across all hardware products.
Cisco IOS Packaging in Release 15M&T for Cisco routers previously supported in
Release 12.4T is shown below:

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Cisco IOS Packaging for Cisco Integrated Services Routers Generation 2
Cisco Integrated Services Routers Generation 2 (ISR G2) 1900, 2900, and 3900 Series
support services on demand through the use of software licensing which enables
customers to realize operational savings through ease of software ordering and
management. When you order a new ISR G2 platform, the router is shipped with a single
universal IOS software image and corresponding feature set packages as shown below.

Please note that Hardware-specific feature sets may affect respective Cisco IOS
Software Package availability.
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Cisco IOS Software Activation for Integrated Services Routers Generation 2
Software Activation enables an `On Demand Service’ activation model for Cisco ISR G2
and supported network modules with consistent licensing policies and manageability as
available on other Cisco Software Activation platforms. Customers will realize operational
savings through reduced truck rolls, ease of software ordering, simplified software
management and greater flexibility in deploying new features.

Each ISR G2 router will ship with a universal Cisco IOS Software image andwill use
Software Activation Licensing keys to activate IOS functionality. Features ordered with
the router will be pre-activated at the factory or by your Cisco partner.

FAQ of Cisco IOS Software 15M&T Releases
Q.What is the relationship between Cisco IOS 15 M and 15 T releases?
A.Both 15 M and 15 T releases integrate new technologies and features, new hardware
support, and provide ongoing software maintenance (via maintenance rebuilds) on a
regular, ongoing, basis over the support lifecycle for the release.
Release 15 M (Extended Maintenance)
Ideal for long-term maintenance, enabling customers to qualify, deploy, and remain on
the release for an extended period.
Provides approximately 40 months of total support.
Incorporates features delivered in previous releases plus incremental new feature
enhancements and hardware support.
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Release 15 T (Standard Maintenance)
Short deployment releases ideal for latest new features and hardware support before the
next extended maintenance 15 M release becomes available.
Provides 19 months of support.
Incorporates features and hardware support delivered in previous releases.

Q.What is the release numbering schemes for 15 M and 15 T releases?
A.The formal numbering scheme for both 15 M and 15 T releases is shown below:
Release 15 M numbering. The letter M after the parenthesis denotes Extended
Maintenance release.

Release 15 T numbering. The letter T after the parenthesis denotes Standard
Maintenance release.

Q.What is the numbering scheme for maintenance rebuilds of 15 M and 15 T
releases?

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A.As illustrated below, the number directly after the M or T, with the exception of the initial
new feature release, is the maintenance rebuild number of the release. No new features
or hardware support are delivered in maintenance rebuilds of Release 15 M or 15 T.

Release 15.0(1)M includes incremental new software features and hardware support,
features previously delivered in Release 12.4T, and software fixes
After its initial introduction, Release 15.0(1)M will receive ongoing maintenance (bug
fixes) through release rebuilds
Rebuilds are identified by a release number suffix increment:
The 1st maintenance rebuild of Release 15.0(1)M is numbered 15.0(1)M1
The 2nd maintenance rebuild of Release 15.0(1)M is numbered 15.0(1)M2
The 1st maintenance rebuild of Release 15.1(1)T is numbered 15.1(1)T1
The 2nd maintenance rebuild of Release 15.1(1)T is numbered 15.1(1)T2

Q.What’s the first new feature 15 M (Extended Maintenance) release?
Cisco IOS Software Release 15.0(1)M is the first 15 M (Extended Maintenance) release.

Q.What’s the first new feature 15 T (Standard Maintenance) release?
Cisco IOS Software Release 15.(1)1T is the first 15 T (Standard Maintenance) release.

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Q.Does Release 15.1(1)T contain features and hardware support delivered before?
Release 15.1(1)T has support for feature delivered in Release 15.0(1)M (and prior
releases), as well as incremental new features.

Q. What IPv6 packaging changes are in Cisco IOS Software Release 15M&T?
A. For years, Cisco IOS Software has expanded support of IP Version 6 (IPv6) to the
majority of its technology areas and hardware platforms Due to market trends such as
available IPv4 address pool exhaustion and regional registries issuing advisory to the
Internet community to adopt IPv6 and national mandates, Cisco IOS packaging for IPv6
is now evolving.
Cisco will support packaging parity for IPv6 with IPv4, for Cisco Integrated Services
Routers Generation 2, starting with Cisco IOS Software Release 15.0(1)M, as well as in
future 15 M and 15 T releases. IPv6 feature support for a technology will now be
packaged in the same feature set as IPv4.

Q. What are release notes and caveats?
A. Caveats describe unexpected behavior (i.e.: software defect) in Cisco IOS Software
releases. Release notes include detailed descriptions on Cisco IOS Software Release
15M&T features, a list of resolved caveats from the most recent maintenance release, as
well as a list of open caveats and any existing workaround. Release notes are available
at: http://www.cisco.com/cisco/web/psa/default.html

Q.Where can I find additional information and collateral about Release 15M&T?
A. http://www.cisco.com/go/ios

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