What is SIP Trunking?

SIP trunking is the delivery of inbound and outbound phone service over a data connection using a combination of the session initiation protocol (SIP) and real-time transport protocol (RTP)

  • SIP = signalling
  • RTP = media

More simply it is dial tone over the Internet.

How many concurrent calls can be on a channelized SIP trunk?

The limitation is based on Internet bandwidth capacity and the number of channels ordered. Each non-compressed call uses approximately 85kbps of bandwidth. In most Internet connections your upload speed is normally your slower speed so when determining the number of calls your connection will support use your upload speed. If for example your upload speed on your Internet connection is 4Mbps, then the maximum number of calls would be 47 (4,000,000/85,000).

However, this is ideal and does not include any capacity for other Internet traffic such web browsing, email, etc…

Channelized service allows businesses a way to easily budget their telecom spending, if additional capacity is needed then more channels can be added by updating your account through the Digium portal.

Moving?  What do I need to do?

The great news about a cloud service is that it is effectively available from anywhere.  However, to ensure limited interruptions in your service, please refer to our Moving FAQ document by clicking here

What happens if my Internet connection goes down?

If your Internet connection fails, your SIP Trunk will be unable to process inbound or outbound calls. We encourage you to make our Remote Call Forwarding (RCF) feature part of your business continuity plan. RCF is a feature that allows your incoming calls to be redirected to working numbers, when the need arises. Please review our Remote Call Forwarding (RCF) article for details.

Service Area

Where is Digium Cloud’s SIP trunking available?

Digium Cloud’s SIP trunking is only available in the US48.

Where is SIPStation SIP trunking available?

SIPStation SIP trunking is available in the US48 and Canada. Visit SIPStation.com to sign up.

SIPStation SIP trunking is also available in the UK. Visit SIPStation.co.uk to sign up.

Can I make extended area or international calls?

Yes. To request the ability to make extended area or international calls you will have to enable the services through the Digium Cloud SIP trunking portal or contact Digium Customer Service. All extended area and international calls are billed at per minute rate, and rates will vary depending on area/country.

What is extended area?

Extended area includes Hawaii, Alaska and the Caribbean.

Supported Features

Are toll-free numbers available?

Yes. Digium Cloud’s SIP trunking supports inbound toll-free numbers. Toll-free service is available as a metered service only.

Can I port my existing telephone numbers to Digium Cloud’s SIP trunking service?


What voice codecs are supported?

Digium Cloud’s SIP trunking supports G.711, G.729, and G.722 codecs. As calls can be made anywhere, the only guaranteed code is G.711 because it is the default for non-compressed voice. G.729 and G.722 require that the call remain as SIP until reaching the remote end and the ability of the remote site to support the same codec.

Is T.38 fax supported?

Yes, we support T.38. DCS SIP Trunking simply passes through the T.38 signaling. We do not do any conversion from traditional fax tones to T.38 or vice versa.

Is E911 service provided for my DIDs?

Yes. In fact, an E911 DID is required in order to use Digium SIP Trunking.
You will be required to specify a location for each E911 DID you have. This physical address will be used to route calls to the closest PSAP (Public Safety Answering Point).

Why is 911 DID required for SIP trunking?

Digium Cloud’s terms require at least one E911 number per SIP trunk. This is necessary to provide emergency services. There can be multiple channels or numbers per SIP trunk, but only one E911 enabled number is required.

What happens if I can’t find a DID within the area code and/or prefix I want?

We do our best to accommodate all requests for specified area codes and prefixes. Sometimes this is not possible due to number availability. If you are unable to find the area code and/or prefix you need, please contact a Digium representative.

Do you support Caller ID and Caller ID Name (CNAM) for inbound calls?

Yes. Caller ID and CNAM are supported on all incoming calls; however, the upstream carrier must provide this information in order for us to present it to you.

Do you support Caller ID and Caller ID Name (CNAM) for outbound calls?

Yes. Caller ID is delivered on all outbound calls. CNAM is available upon request and is dependent upon local serving area.

How do I update my Caller ID?

Please complete a request to update caller id with the below information:

Please make sure that the caller ID field is the same as your request. You can check these in your account.

Once this information has been received, we will submit a request to your existing carrier to update your caller ID, which could take up to 15 business days. As soon as everything has been updated on our end, we will notify you through email. Please note it may take up to 4 weeks for nationwide carriers to update their databases, and this process cannot be expedited.

We are unable to update toll free numbers and fax numbers.

  • Phone number(s) that will have the caller ID changed
  • Address
  • Exactly what you would like for the caller ID to say – Must be 15 characters or less, including spaces
  • Account security PIN number

How can I port out my number?

Digium Cloud Services (DCS) uses carriers to provide service for your numbers. DCS does not get involved with port out(s); that request is made by your new winning carrier to the carrier that hosts our numbers. Your new carrier should have a process similar to DCS’s process.

What if I need to cancel a port?

If your porting request has been accepted for an exact porting date, then we require 48-hour notice and charge $25 fee per number for any necessary cancellations. To cancel a port, please contact DCS customer service.

Do you support Remote Call Forwarding?

Yes. Please review our Remote Call Forwarding (RCF) article for details.

Number Porting

How do I port my number to your service?

You must have a Digium Cloud Services (DCS) account in order to port your numbers to us. Please contact Sales at (256) 428-6271 to get started or complete this form to request a number port.

How do I know if my telephone numbers are portable?

Digium Cloud Services can check their portability for you. Simply complete the web form with the name of the carrier from which you are porting and the numbers you would like to have ported.

My current provider says my numbers are portable, but you say they are not. Why?

Digium Cloud Services uses hosted providers to port in the telephone numbers, and the rate center (or prefix) the phone number belongs to is not serviced by our carriers. However, if this specific number is not needed, we can assign a new, similar phone number to you under our service.

Am I able to port my telephone number as fax or voice?

Digium Cloud Services can only port your telephone number as either fax or voice; it cannot be used as both.

How much does it cost to port my numbers to you?

You will be responsible to pay your current provider and DCS for service during the porting process. The fee to port your numbers varies depending on whether it is a local or toll-free number. Review pricing.

Where do I get my LOA form?

A completed Letter of Agency (LOA) is required by the carrier working with Digium Cloud Services (DCS). After an order is placed for a number port, DCS will contact you to complete the LOA.

What information needs to be on the LOA?

The LOA must contain the exact authorized name, billing telephone number, and service address that the current provider has on the Customer Service Record (CSR). If there is any error in the information, the request will be rejected and the number porting process will be delayed. To ensure the LOA contains the correct information, reference the most recent bill from the current carrier or contact the current carrier to verify account information or to request a CSR.

Do I have to provide a bill with my LOA?

Yes, please provide the most recent bill from the current carrier.

How will I know you received my porting forms?

Within 48 hours of receiving a faxed or emailed LOA, DCS will send an email confirmation. To check the status of a number porting order, respond to the Case that was opened to track the status. If the Case email is lost, complete this form.

How long will the porting process take?

Customers should expect to have their number porting completed within 2 to 4 weeks of submitting their request. Digium Cloud Services (DCS) will monitor the status of the port request and will send the customer an email as soon as the losing carrier has confirmed a scheduled port date. Please note, submitting incorrect or erroneous information could delay this process up to 8 weeks.

Can I expedite the number porting process?

Ports cannot be expedited. DCS works to port numbers as quickly as possible, but it can take 2 to 4 weeks for a port to complete. There are steps you can take to try and ensure an expedient port, these include:

  • Fill out your LOA with all of the correct information and return it as quickly as possible.
  • Contact your current carrier to verify your account information and that no pending orders are currently processing on your account.
  • Provide DCS Porting with a direct contact name, number, and e-mail of a representative with your current carrier who will approve and assist in expediting your port. Please note most carriers will only assist in expediting a port if you currently have escalated phone issues that are disrupting your service.

What could delay the porting process?

The most important aspect of a port request is correct information. The LOA must contain the exact name, billing phone number, and service address that the current provider has on the CSR. If there is any error in the information, the request will be rejected and the number porting process will be delayed. There are other factors that may slow down the porting process, such as:

  • The LOA and copy of the losing provider's bill are not dated within the last 30 days.
  • A pending order on your account.
  • The losing carrier is backlogged with port out orders.

How can I set up temporary numbers for forwarding?

Digium Cloud Services (DCS) will automatically assign temporary numbers for your carrier to forward to while waiting on your number(s) to be ported. DCS will bill for the use of these DID numbers. Once your porting is complete, DCS will deactivate the temporary numbers. If you would like to maintain these temporary DIDs, please contact DCS customer service before your port completes to request retaining temporary DIDs.

Can you contact my current carrier and forward my telephone numbers for me?

No, Digium Cloud Services does not have the authorization to make any changes to existing accounts with other carriers.

Will I have downtime during the port?

Digium Cloud Services strives to have zero downtime during your number porting. Temporary numbers are provided that will allow you to instruct your losing carrier to forward calls to you while awaiting the port.

Digium Cloud Services (DCS) will load the numbers into our system and assign them to your account before the port date. Please make sure the numbers to be ported are properly configured to point to the correct location, an employee, call queue, or an IVR, on or before the date of completion in order for them to work properly after the port.

You may also contact DCS with porting instructions for assigning your numbers.

What time of day will my numbers port?

All DCS incoming ports are completed by 7:00 pm EST.

How do I know the status of my port?

Digium Cloud Services (DCS) monitors the status of the port request and will send the customer an email as soon as the losing carrier has confirmed a scheduled port date. You may also request a port status update.

What do I do if my ported number is not working?

If you experience any problems with your number, please contact Digium technical support as soon as possible at 877-865-4032.

When is it okay to cancel service with my existing carrier?

Disconnected numbers cannot be ported, so it is imperative to wait until Digium Cloud Services has ported all telephone numbers before you cancel the existing service. We recommend waiting at least two days after porting has been completed before you contact the losing provider. While canceling service, please ensure the losing provider will be removing the ported telephone numbers from its database.

Can DCS cancel my service with the losing provider for me?

No, Digium Cloud Services (DCS) does not have authorization to make any changes to existing accounts with other carriers. After the phone numbers have been ported over, please contact your existing provider and cancel the service.

What do I do if my carriers released my numbers but I have not received notice from DCS?

If your carrier releases your numbers without advanced notice or you experience any problems with your number, please contact Digium Technical support as soon as possible at 877-865-4032. Please remember if you cancel service before your number port is complete, then your losing carrier can release your numbers. After numbers are released, they CANNOT be ported.

Why has my port been rejected?

The current carrier may reject the request to port your telephone number because there was incorrect information on your request, a pending order on your account, or a feature removal needed. When a port request is rejected, DCS Porting sends you an email with the exact reason for rejection and information for how to resolve the issue with the current carrier. You must contact your existing provider to obtain the correct information or to resolve the issue. After the issue has been resolved, please let DCS know so we may resubmit the request for you.

Can I port my number from Digium Cloud Services (DCS) to another carrier?

Digium Cloud Services Accounts

Where can I view my billing invoice?

Login to your Digium Cloud Services Customer Portal at my.digiumcloud.com. Then click on “Invoices”.

When do I get billed?

Billing is based on your service activation date or the date you selected to be billed.

Can I change my bill date?

No, after billing starts there is not a way to change the billing date.

Will I receive a paper invoice?

Digium Cloud Services does not provide paper invoices. Invoice notifications are emailed to your email address on file. This email notifies you that an invoice is now available. Invoices are available for viewing or download via our Cloud Customer Portal at my.digiumcloud.com.

I have questions about my invoice, who do I call?

Please contact our Customer Success team at 256.428.6175 or [email protected].

How can I update or change my billing information (credit card, invoice recipients, etc.)?

Access our Cloud Customer Portal at my.digiumcloud.com. Click on “Payment Info”. In this section, you can update your payment info, billing address, or invoice recipients.

How do I know if my payment was processed?

If your credit card is declined, you will be notified via email the same day. Be sure your email address is up to date on your account. It’s easy to update your info at my.digiumcloud.com.

Why has my service been suspended or disconnected?

Service can be suspended or disconnected for the following reasons:

  • Non-payment
  • Fraud or misuse of service
  • Service termination

How do I reactivate my service if it has been disconnected for non-payment?

Accounts with outstanding balances for 15 days or longer must be brought up to date immediately to avoid service disruption. Service can be restored by paying the outstanding balance on the account and any additional fees incurred. Please contact the Digium Cloud Services Accounting team at 256.428.6153 or [email protected] for additional information. Please note, you have 10 days to reactivate service before all phone numbers associated with your service are released and thus unavailable after this period.

How do I request a credit for incorrect charges on my account?

Please contact our Customer Success team at 256.428.6175 or [email protected].

Can I cancel my service at any time?

This depends on your contract terms. All cancellations require a 30 day notice. If your account is on a month to month subscription, then all that is required is the 30 day notice. If you have have a yearly contract, then you are required to fulfill the remaining terms of your contract; otherwise, you will be billed for the remaining months of service left to satisfy your contract term. Please see the Digium Cloud Services Terms of Service for detailed info or contact our Customer Success team at 256.428.6175 or [email protected].

How do you handle tax exemptions?

In order to have the correct taxation applied to your invoices, you must provide DCS Accounting your tax exempt certifications. You will be asked to email a copy of your tax exemption certificates to [email protected] at the end of your setup (onboarding) wizard. DCS will then have a 3rd party review your records. If no certificates are sent to DCS Accounting, we cannot apply tax exemptions to your account. Digium cannot provide credit for previous paid taxes if tax exempt status is not provided at time of service activation.

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