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Aleksandar Vidakovic
Cisco Employee
Cisco Employee


The purpose of this document is to help you understand the IOS XR software release strategy and help you select the optimal IOS XR release for deployment in your production network. 

This content of this document, including the projected release dates, should be understood only as a guideline. I suggest that you always contact your account team at Cisco to obtain a the IOS XR suggestion for your specific deployment scenario.

Official information on IOS XR releases is available in the "Guidelines for Cisco IOS XR Software"document.

What Is An Extended Maintenance Release (EMR)

For us at Cisco it is very important to deliver the new features and hardware that your network requires, while at the same time maintain the high software quality. We are continuously investing efforts to improve the quality of our software and hardware. We are adjusting our culture, processes and practices to achieve that goal.

One of the key concepts in the software quality plan is the Extended Maintenance Release (EMR) introduced in IOS XR for the first time with the release 4.3.4.

Extended Maintenance Release (EMR) criteria:

  • No new software features
  • No new HW support
  • Incoming bug rate to drop by at least 90% from peak rate for that release.
  • Zero critical bugs.

By choosing the EMR for deployment, you are making the optimal choice. We will be happy to work with you on EMR early field trials or any other way to help synchronise your upgrade/migration plan with the EMR release schedule.


By selecting the EMR you are not only making sure that you are getting the best quality release, you are also selecting a release with the highest deployment rate.


Benefit Of Upgrading To A Most Recent EMR

A comparison of XR 6.4.2 and 5.3.3 illustrates the benefit of upgrading to a recent EMR: 

Software Stability

  • Improved Software Stability:
    • Reduced number of SMU’s and SMU’s that need reboot. 59% Improvement, normalising by Installed base, in the last 3 years.
    • 42% Improvement on Sev. 1&2 SW defects (2019 Vs. 2017).
  • Improved system debuggability


  • Enhanced Network Availability
  • Reduced Time to Restore
  • Reduced Business Impact and operational costs

Software Quality

  • Improved SW Quality:
    • Reduced Number of SW Incidents 58% Improvement of 6.4.2 Vs. 5.3.3. normalizing SW defects by Installed base (3 Years timeframe)
    • 40% Improvement of 6.4.2 Vs. 5.3.4. (≈ 2 years timeframe)
    • Improved system debuggability


  • Enhanced Operational Excellence
  • Reduced time to Resolution
  • Reduced Operational Cost

Vulnerability Risk:

  • Reduced PSIRT exposure

New functionalities:

  • New Features for new Services



Managing Your IOS XR Install Base

Keeping your IOS XR installation up to date with is very important. We continue providing software patches through Software Maintenance Units (SMUs) and Service Packs (SPs).


Manual SMU and SP install is a thing of the past since the introduction of the CSM Server. CSM Server is a web based server side automation and orchestration framework designed to ease the SW maintenance for all IOS XR platforms. After installing CSM Server 4.0, in-application upgrade is available for keeping your CSM Server application up to date.


To get the glimpse of the CSM Server we highly recommend to watch the _video_. CSM Server distribution comes with a documentation included, but you can also read more about it on _supportforums_.


Another benefit of deploying EMR is that more software patches are available compared to other releases. Number of software patches (SMUs) available per release is directly proportional to the number of our customers running the release. Also, on EMR we try to provide, when technically feasible, SMUs for issues affecting the usability of IOS XR, not only for critical issues directly impacting the services. Service Packs (SPs) are also built more frequently compared to non-EMR releases.


SMU and SP concepts are explained in the "Service Pack Overview for Routers that Run Cisco IOS XR" document.


Service Packs on are built on EMR every 8 weeks. On non-EMR builds are on-demand, but never more frequent than on EMR.


Before the introduction of CSM Server, deriving the optimised SMU list for a given install base was a challenging task. Service Pack (SP) was introduced to deliver on operational simplicity.


On 32-bit IOS XR, SP is a single package that can be installed on the system regardless of the active base packages. For example, if BNG package is not active on the system, all BNG elements in the SP are ignored during SP activation.


On 64-bit IS XR, SP is a tarball containing the optimised set of production SMUs posted to date. User should unpack the tarball and install only the RPMs of interest individually or by re-packaging them into a new tarball. For better alignment to the SP concept, from year 2021 onwards the 64-bit SP will be provided in a form of a Golden ISO image.


If you are using CSM Server to manage your install base, CSM Server optimises the SMU set for you, allows you to define "software profiles" (set of base packages plus SMUs or SP) and allows you to easily install the same profile on multiple nodes. You can also run conformance reports. With this CSM Server functionality, the choice between SMU and SP is really down to a user preference. CSM Server delivers the same operational simplicity for users who prefer SMU over SP or vice versa.

64-bit vs 32-bit IOS XR

The 64-bit flavour of IOS XR is available for ASR9000 starting from XR release 6.1.2. Up to and including IOS XR major release 6.6.x,  there is no different release number for the 32-bit and 64-bit IOS XR. The 64-bit software packages are designated by the 'x64' in the package name (e.g. ASR9K-x64-iosxr-px-6.1.2.tar). Split between 32-bit and 64-bit release numbering starts with IOS XR major release 7.0.x. As a consequence, the 7.x.x releases are available only for 64-bit capable platforms. Support for 32-bit IOS XR on ASR9000 continues with 6.7.x, 6.8.x, etc.


For more information, including the required minimum hardware for running 64-bit IOS XR on ASR 9000 platform, refer to the "Cisco ASR 9000 Series IOS XR 64 Bit Data Sheet".


CSM Server contains a module that seamlessly performs the migration from 32-bit XR to 64-bit XR. We highly recommend you to watch this short demo video.


New IOS XR platforms NCS500, NCS5000, NCS5500 and 8000 only support the 64-bit flavour.


Suggestions For Year 2021

Following table shows the suggested releases for general deployment in calendar year 2022. We may decide to provide a further release update (e.g. 7.5.3) for some specific deployment scenarios on specific platforms. If you would like to know whether your deployment scenario falls into that category please reach out to your account team at Cisco.


Platform Release Comment
8000 7.3.3, 7.5.2

7.3.3 is EMR for Cisco 8000. Not planned for other platforms.

7.5.2 is an EMR for all XR platforms.

ASR9000 7.3.2 , 7.4.2, 6.8.2, 7.5.2
  • 64-bit XR:
    • 7.3.2 (has no 32-bit equivalent)
    • 7.4.2
  • 32-bit XR:
    • 6.8.2 (32-bit equivalent of 7.4.2)

HW specifics:

  • Last release for A9K-RSP440 is 6.4.2 (EoS-EoL notice)
  • Last release for ASR9k 2nd generation line cards (aka Typhoon) is 6.7.3, except asr9001.
CRS 6.7.4 6.7.4 was released only for CRS
NCS540 7.3.2, 7.4.2, 7.5.2  
NCS560 7.3.2, 7.4.2, 7.5.2  
NCS5000 7.3.2, 7.5.2

These releases are for standalone use of NCS5k. For satellite use, refer to ASR9k SW suggestion.

NCS5500 7.3.2, 7.4.2, 7.5.2  
7.4.2, 7.5.2  
NCS6000 7.2.2  
XRv9000 7.3.2, 7.4.2, 7.5.2  


The following table shows the IOS XR release schedule planning for year 2021.

IOS XR tentative release schedule

Disclaimer: future release dates and numbers are tentative and may change without notice.

(*) LA == Limited Availability. If you need access to this release please contact your account team at Cisco

Release FCS
7.3.2 EMR 2021-12-07  
7.3.3 EMR 2022-01-29
  • EMR for Cisco 8000.
  • Not a General Availability release for other platforms.
7.4.2 EMR 2022-02-16
  • EMR for all IOS XR platforms except Cisco 8000
6.8.2 EMR 2022-03-01
  • ASR9000 32-bit only; equivalent of 7.4.2.
7.5.2 EMR 2022-04-27
  •  EMR for all IOS XR platforms except Cisco 8000
7.5.3 EMR 2022-Q3
  • EMR for Cisco 8000
  • Not a General Availability release for other platforms.
7.6.2 2022-Q3  


We hope you find this document useful. Happy roll-out of IOS XR!


Related Documentation



@Aleksandar Vidakovic 


I am planning to upgrade ASR9006 (RSP440) to the latest software and that is 6.4 release (current 6.4.2).


At the moment i guess I should install v6.4.2 and SP asr9k-px-6.4.2.k9-sp9.tar to get the latest fixes?

Will there be sp10 version because there are SMU released after release date for sp9?

Is there going to be v6.4.3 that will incorporate SMU and SP available for v6.4.2.


At the moment CSM Server  is not an option.





Aleksandar Vidakovic
Cisco Employee
Cisco Employee



hi Ivan,


you're right. If you can't go beyond 6.4.2, recommendation is to deploy 6.4.2 plus Service Pack 9. There will be SP10, sometime in late September.


We're not planning on delivering 6.4.3. That release was exceptionally created for CRS, but not for any other platform.


I would also suggest that you contact your account team at Cisco to inquire about the options for upgrading from RSP440 to RSP880-LT. That would allow you to upgrade to 6.7.3.


Hope this helps,


Garry Peirce

Hi Aleksandar,


As 7.3.2 EMR has yet to be released for the 9k, curious if you may have any insight if better to upgrade to 7.1.3 with it's many SMUs or go to 7.3.1 with it's few SMUs (at this point) instead.

Does 7.3.1 have many of the 7.1.3 SMUs included?


thank you,



Hello Aleksandar,

will you update the release schedule? Since 7.5.1 was released it would be interesting when EMR for 7.5 branch is planned for each platform.



Andreas Kalb
Cisco Employee
Cisco Employee


plan for 7.5.2 is EoApril '22, which might change over time.

Kind Regards,



Sorry, the sharepoint link seems not to be public. I can not access it. Seems to be Cisco internal.

Andreas Kalb
Cisco Employee
Cisco Employee

sorry then, especially as I seem to have shared internal info, because I wasn't aware of the article/site being public. I’ll delete that info now.

Kind Regards,


Hi there,

when is IOSXR-7.5.2 coming out?

compared to 7.3.2 what will have more?

Aleksandar Vidakovic
Cisco Employee
Cisco Employee



hi Massimiliano,

7.5.2 should be available for download by the end of April. For new features listing, consult the Release Notes of 7.5.1 and after 7.5.2 is posted also the Release Notes of 7.5.2. Note that 7.5.2 is an EMR, so it will not have any new feature. Some enhancements may be included.




Hi, just wondering if it's possible to upgrade ASR-9001 directly to 6.8.2 from 6.4.2?

Thanks heaps



Is CSM Server still maintained? I am asking this, because I can not see anything on the "Release Software" tab in CCO section for ASR9K-X64 for software releases >= 7.4.2

Aleksandar Vidakovic
Cisco Employee
Cisco Employee

Hi @mw79 ,


CSM Server functionality should now be part of the Crossworks framework. CSM Server as standalone product is not active any more.



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