Skip to main content

Stage 5 - call off, implementation and migration

Part of the HSCN journey for customer led procurements.

Further details on this stage will be published in due course. The paragraphs below summarise this stage. 

Stage 5 consists of the three following phases:

Call-off - contract signature

The process by which consumers will place orders for new HSCN services from a HSCN compliant supplier. For customers engaged in a collaborative procurement, this will depend on the specific arrangements that have been agreed. Broadly however, the activity will include:

  1. Due diligence - upon receipt of a new order, the consumer network service provider (CNSP) will engage with the consumer to perform due diligence activities. These will often involve requests for additional information, conducting site surveys and confirming the services and connections currently in place.
  2. Order placement - once the due diligence is complete, the CNSP will be able to confirm a new order and advise a firm order confirmation date. The delivery date will depend based upon the services ordered and availability within your local area. 

A CNSP is any HSCN supplier engaged in providing HSCN services to customers.


The HSCN Migration Checklist provides details of the actions you'll need to take at each stage of your migration to HSCN from the Transition Network and should be consulted at all stages of your HSCN migration journey.

Involves the delivery, testing and sign-off of new HSCN services. Implementation of new access connectivity services will include:

  1. Circuit delivery - provision of a new service to the customer premises. 
  2. Commissioning tests - a set of tests to ensure the new access connectivity services are functioning as expected. This will often involve a customer sign-off from an appropriate individual.


Migration involves cutting-over from existing legacy connectivity to the new HSCN service shortly after the replacement service is commissioned. Migration activities will vary dependent on the circumstances but for a new replacement service will typically involve:

  1. A go/no-go decision - a decision point with the appropriate stakeholders to confirm the new service is live and all parties ready to proceed with migration.
  2. Pre-migration tests - a set of checks to confirm access to production applications is available before the start of migration.
  3. Network changes - a set of activities to cutover to the new service. 
  4. Post-migration tests - a set of checks to confirm the network change has been completed successfully and access to production applications is available. 
  5. Go/no-go point - in the event that the post-migration tests have identified an issue, there should be a planned decision point to agree whether to roll-back or attempt to investigate and resolve the issue. In the event of rollback, the migration will need to be rescheduled. 
  6. Regression testing - depending on the customer organization, additional IT infrastructure and business application tests may be performed to provide assurance that these are unaffected by the network change. 
  7. Migration complete - once all tests are satisfactorily complete, the customer should sign-off the migration complete with the parties involved.

Both the implementation and migration activities should adhere to your normal change management governance and procedures.

Last edited: 21 May 2019 3:01 pm