What is SIP Trunking and what is a SIP trunk carrier?
Home > What is SIP Trunking and SIP services?
SIP trunking is a method by which business phone systems can operate using an Internet connection instead of a traditional phone line.
SIP Trunking:
Costs Less
Scales Easier
Offers More Reliability
How Does SIP Trunking Work?
SIP trunking works with VoIP phone systems (Voice Over Internet Protocol) and is based on SIP (Session Initiation Protocol).
SIP, which is the basis of SIP trunking, is the standard communications protocol for voice and video in a Unified Communications (UC) solution across a data network.
SIP trunking eliminates the physical connection to a phone company. There are no hardware, wiring, or circuit boxes to maintain for connection to the PSTN.
A SIP “trunk” is installed virtually over your business’s existing Internet connection, therefore replacing the need for traditional analog phone lines.
Reducing multiple phone lines into a single point of entry drastically reduces charges for incoming lines and the IT cost associated with the maintenance of those lines. (Some organizations prefer to maintain standard lines for faxes and alarms.)
SIP Trunking with Your Phone System
Many companies already use VoIP within their phone system on the Local Area Network (LAN) to connect to IP phones.
SIP trunking also uses VoIP to take advantage of shared lines, such as a company’s Internet connection, to allow more flexibility in communications.
Traditional phone systems (that aren’t already VoIP-capable) can be connected using common VoIP gateways to take advantage of SIP trunking and reap the significant cost benefits.
What is a Direct Inward Dialing Number (DID)
Benefits of DID SIP Trunking
Cost Savings
- High monthly phone bills
- Costly charges for incoming phone lines
- Long distance charges
- IT and maintenance fees
- Constraints of limited communications technology
Scalability
Reliability
SIP trunking with VoIP increases reliability of services by providing a level of redundancy. When system failures and emergencies occur, SIP trunking providers can reroute services to a redundant data line or forward the PBX to mobile phones to keep your business up and running.
Other Benefits of SIP Services
- Works with most modern phones
- Ability to transfer and use your old phone numbers
- Affordable phone numbers for all your team members
- Less maintenance – No longer have to maintain analog and IP infrastructure
SIP Trunking vs. PRI (Primary Rate Interface)
If you’ve been shopping around for business phone systems, you’ve probably come across the term Primary Rate Interface (PRI). You’ll often hear people compare PRI to SIP trunking, and it’s important to know the pros and cons of each before making a decision.
PRI and SIP trunking are two different ways to “connect” your phone system to the outside world. On the most basic level, SIP trunking uses your Internet connection to make phone calls, while PRI uses a dedicated physical connection.
PRI (Primary Rate Interface)Uses Traditional Phone lines |
SIP TrunkingUses existing Internet connection |
---|---|
PRI Pros:
PRI Cons:
|
SIP Services Pros:
SIP Services Cons:
|
SIP Trunking vs. VoIP
Questions to Ask When Switching to SIP Trunking
To prepare your company for SIP trunking, you first need to consider a few questions.
How many people are on the phone at the same time during your busiest hours?
That will determine how many channels you will need. SIP trunks allow for quick and easy scaling, so you may add or remove channels as needed if you under or overestimate.
Will your call volume remain fairly consistent from week to week, or will it fluctuate?
With SIP trunking, you can purchase channels. When call volume increases, Concurrency Bursting allows you to burst beyond the number of channels you have. This is explained more on our SIP trunking pricing page.
Will you need to scale or add new users relatively quickly?
This is an important factor, particularly when deciding between on-premise and hosted phone systems. Click here to learn more about hosted vs. on-premise options.
What to look for when selecting a SIP trunk carrier?
- Watch out for contracts - choose a SIP trunk carrier that allows you to cancel or reduce the number of channels whenever necessary
- Check if there are hidden fees - consider federal fees, taxes and an additional charge for each channel.
- Make sure the SIP trunk carrier includes short and long-term support - while SIP is fairly user friendly, it’s always a good idea to have support in case there any issues
- Adding channels on demand - An important feature to consider as you anticipate growth in your organization to make scaling as simple as possible
- Capability to port current phone numbers and get new DID numbers - Also, be sure they have a large DID network so can get the international and local numbers necessary.
Is Your Network Ready for SIP Trunking?
Network considerations that must be examined include total available bandwidth, Quality of Service, and firewalls. Upgrading your Internet connection may be necessary to ensure sufficient bandwidth to carry a new phone system on top of typical Internet usage for your company.
Quality of Service (QoS):
Equally important to bandwidth is Quality of Service. QoS prioritizes your voice traffic and ensures that your phone calls are going to get the bandwidth needed, regardless of what else is happening on the network. The vast majority of business grade network routers will provide QoS for your network.
Firewall:
A firewall is critical to maintain security both within a LAN and Wide Area Network (WAN). Though firewalls are a critical component to any business network, they must be configured correctly to work well with SIP trunking.
E911:
For safety, it is essential to add Enhanced 911 (E911). E911 is a feature of the 911 emergency-calling systems that places VoIP emergency callers with the appropriate resources by associating a physical address with the calling party’s telephone number.
Network Bandwidth Equation
Use the following simple equation to determine the necessary bandwidth to support your calls:
(number of concurrent calls at your company’s peak)
x
100 kilobits per second
=
bandwidth in Megabits per second (Mbps) needed for calls
SIP Trunking Pricing
SIP trunking pricing varies depending on how many channels you need. Per channel pricing, also known as “channelized”, is great for businesses that prefer a set, predictable monthly phone bill.
To see how much SIP trunking costs, check out our SIP trunking pricing page.
Wholesale SIP Trunking
How Can Sangoma Help You With SIP Trunking?
SIP Trunking by SIPStation
How Does SIP Trunking Work?
How Much Does SIP Trunking Cost?
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