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SIP phone iconSIP Trunk Service


Session Initiation Protocol (SIP) has become the common signaling standard for real-time business communications for Voice over Internet Protocol (VoIP). As a SIP Trunk provider, SIP allows us to packetize and prioritize multimedia traffic over digital circuits, offering higher quality and more reliability than traditional Voice over IP phone service.
As such, SIP Trunks allow for everyone to receive a personal business phone number, but only one phone line is needed. As such, SIP service is typically more cost-effective and scalable than traditional phone service alternatives. And with our geo-redundant platform and failover features, you can rest assured that your business lines will always be accessible.




SIP trunk service diagram showing 1 phone line transmitting voice service to multiple locations in maryland.

SIP Trunks are virtual, “cloud-based” high definition (HD) phone lines that utilize a Broadband connection and your business phone system for access. SIP Trunking enables you to eliminate the cost of maintaining two networks (POTS + Ethernet) by placing your phone traffic on your Ethernet network.
Additionally, SIP Trunks allow two devices to have several different methods of communication streams running, allowing businesses to transmit several calling paths over one channel. SIP allows businesses to network all of their locations under one account, so for example, an inbound call can ring to multiple locations.




Working with our upstream Carriers, ACC Telecom provides SIP Trunking service to on-premise business phone systems and remote employees by utilizing their existing broadband connections. Though SIP is a signaling protocol used within the Voice over IP umbrella, it is inherently faster, more adaptable and scalable than traditional Voice over IP services.
SIP Trunks can carry all forms of media, such as voice, video, and data. SIP can handle large amounts of data and traffic while adapting its signaling protocol to match that of the PBX system. For these reasons, SIP Trunks are preferred by companies that have multiple branches, remote workers, or want to implement a video calling and video conferencing solution.

SIP Trunking Diagram showing how ACC Telecom delivers SIP Trunk service to businesses in Maryland, Washington DC, and Virginia.




The benefits of SIP technology are endless, from small businesses looking for the flexibility and cost savings of Voice over IP phone service to enterprises looking for business network continuity and disaster recovery. SIP Trunking Technology is the perfect solution for businesses that already own a phone system, but want to reduce their monthly phone bill, gain business continuity features, and increase security.
SIP Trunks offer significant advantages over landline phone service, notably the flexibility and price. Analog lines have limited functionality and high costs. SIP Trunks, however, are quality reliable, less expensive, and offer network solutions. Today, with SIP technology, choices are much more dynamic and offer a host of solutions and features tailored to each individual company.

checkmark iconDisaster Recovery & Geo-Redundancy

checkmark iconCost Savings between 40-60%

checkmark iconHD Voice

checkmark iconNationwide Calling + Canada

checkmark iconHacking Prevention w/ Real-time Monitoring

checkmark iconSecure User Portal

checkmark iconCall Accounting Reports

checkmark iconBusiness SMS Text Messaging*

checkmark iconShared Phone Lines Between Multiple Locations

checkmark iconReduced International Calling Rates

checkmark iconVirtual Fax*

checkmark iconConference Bridging*

checkmark iconRobo-call Blocking*

*Optional features


Infographic 5 Benefits of SIP TRUNKS

Top 5 Reasons to Switch to SIP Trunks

SIP Trunks vs ISDN infographic

ISDN vs. SIP Trunks- How They Stack Up




  • Pricing per SIP Channel

  • Nationwide U.S. Calling + Canada
  • PBX License
  • Geo-Redundant
  • Disaster Recovery
  • HD Voice
  • Call Accounting
  • Online User Portal
  • Multi-office Networking
  • SMS Text Messaging

  • Price based on a 10 user account. Pricing may increasing depending upon number of users.

    Starting at


    per month

  • Pricing upon request




How does SIP Trunking differ from traditional phone lines?

Using your companies existing bandwidth, Session Initiation Protocol (SIP) trunks provide a digital version of a phone line by removing the need for physical assets such as wiring and boxes. In addition to this wireless connectivity, SIP Trunks are much more versatile than traditional phone lines, allowing for the transmission of voice messages, data, and video.  Furthermore, companies with multiple offices and remote employees choose SIP trunks because of its networking capabilities. Based on these facts, companies tend to report a 40%-60% savings when switching from traditional phone service to SIP Trunking service.

What are the differences between VoIP and SIP?

Voice over Internet Protocol (VoIP) and Session Initiation Protocol (SIP) may act similar from the outside, but they operate differently.  One of the main differences between the two is their scale.  VoIP enables inbound and outbound calls dedicated to one particular outlet, whereas SIP is a much larger application that has the ability to spread transmissions to many users at once- sending not only voice messages but data and video as well.

Do SIP Trunks use a lot of bandwidth?

SIP Trunks do not use a lot of bandwidth- only 88KB per call.  In comparison, sending an email with a 1-page PDF attachment uses around 180KB.

Do I need a QoS router to use SIP Trunks?

No, a Quality of Service (QoS) router is not necessary to deploy SIP trunking service.

What types of phone systems are compatible with SIP Trunks?

IP, Hybrid, and some digital phone systems are the best PBX systems to deploy a SIP Trunking solution.  We recommend our 3CX IP Phone System because 3CX does not charge per-user licensing, application, or extension fees.

Antiquated phone systems are capable of implementing SIP service by adding a gateway, however, it is not recommended due to reported call quality issues.

What is multi-office networking?

Multi-office networking refers to a company with multiple office locations- including remote workers- that share phone service and PBX features and applications.  Normally, one location will house the on-site IP business phone system while the remaining locations connect to the main hub using IP phones. This enables employees to extension dial, intercom, and seamlessly transfer calls back and forth to various office locations.  Companies that network their locations with SIP Trunks save time and money by:

  • Reducing the number of personnel answering the phones
  • Reducing the number of phone lines and phone numbers needed
  • Combining phone service and eliminating long distance charges
  • Receiving & processing only one invoice for all locations
What is Call Accounting?

Call Accounting provides call details on inbound, outbound, and internal calls.  Our complimentary Call Accounting reporting examples include graphs on call activity, and concurrent call usage.

What is Disaster Recovery?

Disaster Recovery provides automatic failover capabilities so you'll never lose a call during a system failure, power outage or internet outage.

How does SIP Trunking differ from a cloud PBX?

SIP Trunking channels are digital phone lines that provide calling services to businesses with on-premise office phone systems.  SIP Trunks replace traditional landline service.

A Cloud PBX incorporates SIP calling services within its software so all calling services, features and applications are in the cloud.



cloud and phone icon inside circle, indicating SIP Trunking


ACC Telecom is a SIP Trunk provider centrally located in Columbia, MD to conveniently support business phone systems and VoIP phone service throughout Maryland, Washington, D.C., Northern Virginia, and beyond. Contact us for more information on SIP Trunking.

Sip Trunking brochure for businesses in Maryland, Washington DC, and Virginia that are interested in SIP Trunks

SIP Trunk Brochure

It's no secret, ACC has been one of our best providers here at Mount de Sales, and the longevity of our partnership says it all."

— Michael M. IT Administrator, Mount de Sales Academy, Catonsville, MD 21228

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