First Phase: Divert call flow onto redundant systems.
Time: Friday 5/11/2012 5:00-7:00PM Pacific Time
Impact to Service: Possible momentary interruption to service as routing is cutover. Expected duration is under one minute – you may need to hit redial to complete a call or a very long duration call may be dropped and need to be reconnected.

Second Phase: Software, configuration, peering and routing enhancement. Service operating from redundant systems.
Time: Friday 5/11/2012 7:00PM – Saturday 5/12/2012 4:00AM Pacific Time
Impact to Service: No further service interruption. During this period some features will be unavailable: Retrieving voicemail, making any PBX changes via web portal, making any PBX changes via Care, and all external service enhancement software such as Receptionist console, toolbar, etc.

Third Phase: Return callflow to primary systems.
Time: Saturday 5/12/2012 3:00AM-6:00AM Pacific Time
Impact to Service: Service interruption of no more than one hour. The expected duration is 10 minutes.

Once service is restored during phase three there will be no further interruption or limitation to your service.

Work will continue over the following two weeks but no further impact to your service will be required.

If you have any questions you can contact Tierzero Care 24×7 via email to care@tierzero.com or dialing 213-784-1400 option 1.

Voice service will be cut over to a newly acquired group of session border controllers at 11 PM and will remain in service on the new equipment until 11PM Monday February 6th. This maintenance is necessary to allow for testing of the new equipment under full load while minimizing service impact to customers.

Immediately after traffic is cut over a full test plan will be carried out to verify all services are operating as designed on the new equipment and in the case of any failures all traffic can be rapidly rolled back to the stable production environment.

Maintenance Schedule

Event: Cutover to new equipment
Date: February 4th 11PM
Customer Impact: Voice service interruption
Expected Duration: 5 to 15 minutes
Maximum Duration: One Hour

Event: Production environment running on new equipment
Date: February 4th 11PM until February 6th 11PM
Customer Impact: Voice Service – Not expected
Expected Duration: 0 minutes
Maximum Duration: One Hour

Event: Restore normal production environment
Date: February 6th 11PM
Customer Impact: Voice service interruption
Expected Duration: 5 minutes
Maximum Duration: 10 minutes

If you have any questions you can contact Tierzero Care 24×7 via email to care@tierzero.com or dialing 213-784-1400 option 1.