Network and Voice
Voice Lines and SIP Trunking
SIP trunking connects your business phone system to the public telephone network over a data connection, in place of physical phone lines. SIP stands for Session Initiation Protocol, the signaling that sets up and ends a call on a data network.
- 9 companies on the shelf
- Coverage
Buyer's checklist
Eight questions that decide this purchase
Think these through before you buy. Answer what you can and your quote comes back faster. Skip what you cannot, and we will work through it with you.
- 01
Can your phone system accept SIP directly, or does it need a PRI or analog handoff through an adapter?
- 02
What do you have today? Count the PRIs, analog lines and SIP trunks, and note what each one serves.
- 03
How many calls happen at once in your busiest hour? That number sizes the trunk.
- 04
Will voice ride the open internet, your dedicated circuit or a private connection?
- 05
Do any analog lines serve fire alarms, elevators, burglar alarms or fax machines?
- 06
How will a 911 call carry the caller's location, and who keeps those locations current? Kari's Law and RAY BAUM's Act set rules here.
- 07
Must the trunks connect to Microsoft Teams or another cloud calling platform, and by which method?
- 08
What happens when a path fails, and which measures will the provider commit to in writing: jitter, latency, packet loss, time to repair?
No company matches every box you checked
That usually means the combination is rare, not impossible. Clear a filter, or add the service and we will go find who can do it.
Capabilities come from published supplier material. We confirm them for your addresses before anything is quoted.
More on what it is
The lines it replaces come in two kinds. A PRI is a bundle of copper lines delivered to a phone system as one circuit, and it has to be ordered in blocks of 23 call channels. POTS, plain old telephone service, is the single analog line. A SIP trunk carries the same calls virtually, and you add or remove capacity one channel at a time.
Most buyers keep the phone system they have. The trunk connects to the PBX, the on-site phone system already in your closet. If the PBX is too old to accept SIP, an adapter makes the trunk look like the PRI it expects, so you retire the circuit without replacing the hardware. One trunk normally carries local, long distance, toll-free and international calling together, and your existing numbers move with you.
How the trunk reaches you matters more than any feature. It can ride the open internet, a dedicated internet circuit you already have, or the provider's private network. The open internet is the quickest to set up and gives voice no protection. A private or prioritized path keeps calls ahead of other traffic and off the public internet.
A trunk is not tied to a street address, so an office can move or open without ordering new local lines. Providers commonly build in call paths through separate regions with automatic failover. Many offer a web portal, and some an API, so your own staff can change capacity and routing without a ticket. The same trunks can feed a cloud calling platform. Microsoft Teams, for one, accepts outside calling through two methods called Direct Routing and Operator Connect, and a given provider may support one, both or neither.
One more category hides here. Analog lines also serve fire alarm panels, elevator phones, burglar alarms and fax machines. They need their own replacement, usually a device with battery and cellular backup, and a plan that covers only the phones will miss them.
Who needs it
- You have a working on-site phone system and want to keep it.
- You run a call center or contact center and need to size call capacity closely.
- You have many locations and want one voice service managed centrally.
- You still pay for analog lines that serve alarms, elevators or fax machines.
- You use several phone carriers across regions or countries and want one.
- You are a public body that must buy through a government contract vehicle.
If the phone system itself is near the end of its life, look at Cloud Phone Systems first. New trunks will not fix an old PBX.
Signs you need it
- A voice contract or circuit is coming up for renewal.
- Your PRI or analog lines are getting more expensive to keep, or harder to get at all.
- Call volume spikes with the season, and your lines cannot flex to match.
- Voice and data run on separate networks with separate bills.
- Call quality has become a complaint from customers.
- Every small change to your phone service means a ticket to the carrier.
- You are moving other systems to the cloud and want telephony on the same timeline.
How IT Raven helps
Add Voice Lines and SIP Trunking to your quote list and send us a list of your lines, numbers and locations. A person takes that to the voice carriers in our 500+ partner network and sorts them on fit: where they have coverage, how the trunk would reach you, whether they support your phone system or calling platform, and whether an order your size meets their minimum.
We stay on one thread through ordering, testing and the day your numbers move, which is the step that needs the most care. The same team handles added channels, new sites and renewal.
The circuit under the trunk belongs in Business Connectivity, and keeping voice ahead of other traffic across many sites belongs in SD-WAN and SASE. Fax lines have a simpler answer in Hosted Fax.
How buying works
The store is the easy part. Staying on the account is the job.
Anyone can show you logos. The reason to buy here is what happens on install night, and on the ticket you open nine months later.
- 01
Build your quote list
Add services and companies as you shop. No form stands between you and the shelf.
- 02
We bring back real options
A person shops the bench against your addresses, then walks you through what fits and what does not.
- 03
We handle the order and install
Paperwork, site survey, install dates, cutover night. You get one thread, not five vendors.
- 04
We stay on your account
Same team for moves, adds, tickets and the next renewal. That is the part everyone else drops.