Connect Your Existing Phone System to Modern VoIP Service
If your business already owns a SIP-capable phone system, POPP SIP Trunks provide a reliable and cost-effective way to connect that system to the Public Switched Telephone Network using Voice over IP (VoIP) technology.
Rather than replacing your phone system, SIP Trunks allow you to continue using the equipment you already own while taking advantage of modern internet-based voice service.
Whether you’re replacing aging PRI circuits, reducing telecom costs, or expanding your call capacity, POPP SIP Trunks deliver flexible business voice service backed by local support from a Twin Cities provider that’s been serving businesses since 1981.
What are SIP Trunks?
A SIP Trunk is a virtual phone service that connects a SIP-capable business phone system (PBX) to the Public Switched Telephone Network using an internet connection.
A SIP Trunk provides two important components:
- Call Capacity – Each SIP Trunk supports one simultaneous phone call.
- Direct Inward Dial (DID) Numbers – Telephone numbers that allow customers, vendors, and employees to call directly into your business.
For example:
- 5 SIP Trunks = Up to 5 simultaneous calls
- 10 SIP Trunks = Up to 10 simultaneous calls
- 25 SIP Trunks = Up to 25 simultaneous calls
Businesses can use as many DIDs as needed and assign them to employees, departments, locations or specific business functions.
POPP can port your existing business phone numbers to our SIP Trunk service or provide new telephone numbers. We also offer Business Phone Number Hosting and Management services for organizations that need additional flexibility in how their phone numbers are managed and routed.
Because SIP Trunks are delivered over the internet, businesses can easily scale call capacity and telephone numbers as their communication needs change.
➡️Learn more about Business Phone Number Hosting & Management
POPP SIP Trunk Network Map
SIP Trunks vs VoIP Lines: What’s the Difference?
While both services use Voice over IP (VoIP) technology, they are designed for different purposes.
SIP Trunks
SIP Trunks connect directly to a SIP-capable business phone system.
They are best for organizations that:
- Want to keep their existing PBX equipment
- Need multiple call paths
- Need DID phone number routing
- Prefer managing their own phone infrastructure
VoIP Lines
VoIP Lines are designed for individual devices and applications. Like a POTS Line, each VoIP Line has one phone number assigned to it.
- Smaller business phone systems
- Fax machines
- Alarm systems
- Other specialty analog equipment
If your business has a phone system, SIP Trunks are typically the better fit. If you need a standalone phone line for a specific device, VoIP Lines may be the better solution.
Business Calling Features Included
POPP SIP Trunks include reliable business voice service with local and domestic long-distance calling over your existing internet connection.
Each POPP SIP Trunk includes:
- Local calling plan
- Domestic long distance calling plan*
- Caller ID name and number
- Call forwarding
- Call transfer
- Call routing capabilities
- Direct Inward Dial (DID) number capability
- Telephone number portability
*Each SIP Trunk includes 1,000 pooled domestic long-distance minutes per month, helping businesses reduce telecom costs while maintaining predictable monthly billing.
Additional services such as Fax-to-Email, Anywhere Numbers, account codes, and voicemail boxes are also available.
Optimized for Voice Quality
Because SIP Trunks use your internet connection, network quality plays an important role in overall call performance.
A typical voice call uses only approximately 87 kbps of bandwidth, and POPP recommends a reliable business internet connection with at least 1.5 Mbps upload and download capacity.
For organizations seeking maximum voice quality and reliability, POPP offers an optional Voice Management Device (VMD).
The VMD is a professionally managed firewall solution that prioritizes voice traffic over other internet activity, helping ensure clear and consistent phone calls.
Benefits include:
- Improved voice quality
- Reduced call interruptions
- Remote monitoring and management by POPP
- Enhanced troubleshooting capabilities
- Automatic voice failover options for businesses with multiple internet connections
POPP can configure the VMD to function as your primary firewall or work alongside your existing network infrastructure.
Keep Your Existing Phone System — Or Upgrade
One of the biggest advantages of SIP Trunks is the ability to continue using a phone system you’ve already invested in.
For many businesses, keeping an existing SIP-capable PBX is a practical and cost-effective choice.
However, not every phone system is worth keeping.
If your current system is aging, difficult to maintain, or lacks modern features, it may make more sense to move to a cloud-based VoIP Phone System instead.
POPP offers both options and can help you evaluate whether upgrading your existing system with SIP Trunks or migrating to a Cloud Phone System is the better long-term fit for your business.
Why Businesses Choose POPP SIP Trunks
Businesses throughout the Twin Cities choose POPP because we provide:
- Reliable business voice service
- Local, easy-to-reach support from real people
- Flexible call capacity
- Competitive monthly pricing
- Over 45 years of telecommunications experience
- Solutions designed specifically for small and medium-sized businesses
Whether you’re replacing legacy phone circuits or looking for a trusted SIP Trunk provider, POPP can help you modernize your communications while keeping the equipment that already works for your business.
Frequently Asked Questions
What is the difference between SIP Trunks and a Cloud Phone System?
SIP Trunks connect to a phone system that your business owns and maintains onsite. A Cloud Phone System moves the phone system into the cloud, eliminating the need for on-premises PBX equipment.
Businesses with a newer SIP-capable PBX often choose SIP Trunks. Businesses looking to replace aging equipment often choose a Cloud Phone System.
Can I keep my existing phone numbers with POPP SIP Trunks?
Yes. In most cases, existing business phone numbers can be transferred to POPP SIP Trunk service through a process called number porting. This allows businesses to modernize their phone service without changing the phone numbers customers already know.
Do I need the same number of SIP Trunks as DIDs?
Not necessarily. SIP Trunks and Direct Inward Dial (DID) numbers serve different purposes. A SIP Trunk determines how many phone calls can occur at the same time – each SIP Trunk supports one simultaneous call. A DID is a telephone number that callers use to reach your business, department, or employee.
For example, a company might have:
- 10 SIP Trunks to support up to 10 simultaneous calls, and
- 25 DID phone numbers assigned to employees and departments that work over the top of those 10 SIP Trunks
Because SIP Trunks and DIDs are separate resources, businesses can typically add or remove call capacity and phone numbers independently as their needs change.
Can SIP Trunks replace PRI service?
It depends on what your business phone system requires. If your PBX uses PRI today but is SIP-capable, then yes, SIP Trunks are commonly used as a modern replacement for traditional PRI circuits. Many businesses choose SIP Trunks to reduce costs, increase flexibility, and simplify telecom infrastructure while continuing to use their existing phone system.
Does my internet connection affect call quality?
Yes. SIP Trunks use your business internet connection to carry voice traffic, so internet reliability and network performance can impact call quality.
POPP recommends a reliable business internet connection and offers an optional Voice Management Device (VMD) that prioritizes voice traffic to help ensure clear, consistent calls.
Ready to Discuss SIP Trunks?
Contact our team to discuss your current phone system, call volume requirements, and business goals. We’ll help you determine the best fit for your organization.