Planned Maintenance/Outage – SIPLink – Derby – 04/05/16
Posted by Eddie Shortt on 19 April 2016 04:46 PM

After interoperability errors were identified whilst performing the upgrade on Wednesday the 13th April 2016, we have resolved the errors and a resolution has been implemented. As such we will be completing the migration on Wednesday the 4th May to new, upgraded hardware & software. This is to allow for our continued expansion of the platform.

This work will occur between midnight on Wednesday the 4th May 2016 and 3am on Thursday the 5th May 2016. The Derby SIPLink service should be considered At Risk between those times. During the At Risk window the existing cluster will be disconnected from the network and the new cluster connected in replacement. This disconnect will cause all active calls to drop. Node4 engineers will aim to do this at a time of low call traffic where possible to minimise impact.

A change freeze will be put in place from 9am Wednesday the 4th May 2016 to allow engineers to copy the configuration from the old platform onto the new platform and perform appropriate checks. During this change freeze no changes will be made to the Derby SIPLink platform unless they are deemed business critical and approved by the migration team.

Node4’s SIPLink platform in DC3 Leeds will be unaffected by this work.

If you have any questions, please contact the Node4 Service Desk.


UPDATE – This work has now been completed and the new hardware and software has been installed with minimal downtime. We are monitoring the customers using SIPLink and calls the are routing correctly with media flowing in both directions. If, however, you are encountering any problems as a result of this change then please contact us on 0845 123 2229 or raise a support ticket at


Thank you for your patience and cooperation during this maintenance window.

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SIPLink – Issues with STUN connections via
Posted by Scott Miller on 12 April 2016 08:52 PM

Node4 engineers have been alerted to an issue with customers receiving STUN responses via

Should this be causing a problem for any SIPLink connected telephone systems, please use whilst we work to resolve this problem.

We apologise for any inconvenience caused by this issue.

UPDATE – 12/04/2016 23:00 – We believe that the problem has been rectified. Further maintenance is required to mitigate the issue (details to follow on 13/04/2016). If any SIPLink customers that are using the service believe that they have an issue after 23:00 12/04/2016, please raise a support ticket for Node4 UC engineers to investigate.

UPDATE – 13/04/2016 14:40 – The issue experienced was related to a storage issue within the environment that the affected services sit within. Node4 Cloud / Network engineers are currently planning to migrate these services away from their current environment, since it is now legacy. A further update will be provided when this work has been scheduled in detailing the maintenance window / downtime (should this be required).

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Senior Node4 Unified Communication engineers will be performing emergency maintenance on the SIPLink platform (Derby only) to resolve a bug recently identified by vendor TAC.

No service disruption is expected, however the platform is deemed ‘at risk’ between 21:00 and 22:00 GMT on 29/02/16.

Update – 21:42 29/02/2016

This emergency maintenance has been completed without any issues.

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SIPLink – Outbound call Issues to UK mobile destinations
Posted by Scott Miller on 11 January 2016 05:23 PM

We are currently experiencing intermittent call issues to UK mobile destinations.

This is currently under investigation by senior Node4 engineers and a further update will be provided shortly.

If you are experiencing an issue that you believe is related to the above, please raise a Node4 support ticket via or contact support on 08451232229.


Update – 17:44 11/01/2016

A major upstream carrier has notified us of a large incident which is affecting their core network and telephony traffic across their core network.

We have received this statement from them;

“We are investigating an issue that is leading to a degradation of service to several CPs. A technical bridge has been established with a view to understanding the root cause. This has the highest priority within the business and has the full focus of all relevant technical and design communities.”

We expect to have a further update by 18:00. Our own Technical Response Team is currently exploring all avenues to mitigate this outage.


Update – 18:59 11/01/2016

Further to this we have received the following from our carrier:

“A possible issue has been identified on a service providers network that is being investigated. Root cause is unknown at present, however we are working to implement a resolution as soon as possible. Further updates to follow.”

Node4 apologises for any inconvenience this may be causing your business.


Update – 19:50 11/01/2016

Senior Node4 engineers have been monitoring the situation and are also in regular contact with carrier engineers. The outbound traffic to mobiles has now returned to normal indicating that the root cause has been resolved, however we have yet to receive a concrete explanation or resolution.

We will continue to the monitor the situation and provide further updates as they become available.

If you need any further clarification or information then please let us know.


Update – 09:57 12/01/2016

We have received confirmation from our carriers that the issues experienced yesterday are resolved.

This was a major incident that affected BT and the majority of UK mobile operators.  Whilst we have not yet received the root cause report we are assured that the issue has identified and fixed, and our own call analysis shows that the service is performing normally (as of approx. 19:15 11th Jan 16).

Whilst this issue was outside of our control, we would like to apologise for any inconvenience experienced by our customers.  We will continue to work with our carriers to ensure that this is being taken seriously by them, and that they are doing all they can to prevent any re-occurrence.

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