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ISDN30 Service Technology Upgrade

About ISDN30 Service Upgrade

Can I opt out of the technology upgrade to a new Unified Communications platform?

The upgrade is compulsory as the current platform is slated to shut down by the end of December 2023.

Will there be any downtime during the deployment of the new SIP circuit at my premises?

Your services will not be affected during the SIP circuit deployment. However, on the day of the actual upgrade, there will be some downtime of 30 minutes to 2 hours, depending on the number of DDI (Direct Dial-In). You will be notified with the downtime information once available.

Will there be any system configuration change needed for this upgrade?

We will need to deploy an MSBG (Multi-service Business Gateway) to convert our SIP Trunk to ISDN for integration with your PBX (Private Branch Exchange).

If your PBX is capable of supporting a SIP Trunk directly, you have the option to use a direct SIP service, making the MSBG unnecessary. StarHub will provide a new SIP Proxy IP address for you to configure in your PBX to support the direct SIP trunking service. Adoption of a direct SIP Trunking connection to your PBX allows for the option to select the number of SIP channels you require, starting with a minimum of 10 channels and then increasing by increments of 5 channels up to 1000 channels.

Will my phone number remain the same after this upgrade?

Yes, your phone number will remain the same after the upgrade.

How will my users and I benefit from the upgrade?

The new Unified Communications platform is technologically enhanced and allows you to experience new VASes (Value-Added Services), such as subscribing to Voice Recording, SmartSIP for Teams Calling, and SmartUC Mobile Overlay, at a nominal fee.

Will there be any additional charges from StarHub due to this upgrade?

There will not be any additional charges from StarHub.

What should I expect to happen for the entire upgrade process?

From now to 31 December 2023, we will be coordinating a series of activities with you. We will visit your premises to check cabling requirements, after which we will provide you with the SIP circuit deployment date when we will be laying out the circuit at your premises.

After the installation, we will conduct a pre-test onsite before finalising the actual upgrade date. During the upgrade, there will be some downtime of 30 minutes to 2 hours, depending on the number of Direct Dial-in or DDI (<2000 DDI). We strongly recommend that an IT personnel be present so that the new SIP proxy IP address can be configured at your PBX system.

Will my existing contract duration be affected?

Your existing ISDN30 service contract shall remain as status quo.

If I have more queries with this upgrade, who can I contact?

You may email us at or contact your StarHub Account Manager/ Sales Representative.

About Changes to My Billing

What will happen to my StarHub bill?

After the upgrade, you will have a new billing cycle with a new account number that begins with 8.XXXXXXXXX. You will also receive two bills. The first bill will be under your current account number and will cover subscription charges up to the date of the upgrade. The second bill will be under your new account number, and will cover a full subscription charge and pro-rated charges from the date of the upgrade to the end of your new billing cycle. While the charges will remain the same, the second bill will reflect a new service name SmartSIP.

If you have more queries on the bill, you may contact your Sales Representative.

ISDN Upgrade 1

How do I pay bills after the upgrade?

You may pay your bill via the available payment methods listed on our website at

If you have an existing recurring payment arrangement, please note that the recurring credit card payment arrangements will still be applicable but recurring GIRO payment arrangements will need to be reapplied.

I have an existing recurring credit card payment arrangement; do I need to reapply?

Your current recurring credit card payment arrangement will still be applicable to your new StarHub billing account. This is a seamless arrangement with no action required from you.

I have an existing recurring GIRO payment arrangement; do I need to reapply?

Due to bank requirements, you need to reapply for GIRO payment arrangement using your new StarHub account details. The new account details can be found on your new bill.

ISDN upgrade 2

For DBS, OCBC, and other selected banks, you can visit to reapply. If your bank is not on the list, you can download a copy of the GIRO form from our website at and return the completed original form to us using the postage-paid mailer.