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ServicesUnified CommunicationsSIP Trunking

SIP trunking, sized and managed to the carrier.

Concurrent-call channels connecting your on-prem or hosted PBX to the PSTN — channel sizing, DID management, redundancy and failover, least-cost routing, E911, and fraud controls. We’re able to quote and integrate with the carrier platforms we’re partnered with.

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sip · trunk
signalling
SIP · TLS
media
RTP · SRTP
sizing
concurrent channels
delivery
partner carriers
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SIP TRUNK — PBX TO PSTN
Concurrent-call channels, PBX to carrier.
Your on-prem or hosted PBX registers to a SIP trunk we size and manage — a pool of concurrent-call channels — then out to the carrier and PSTN, with a redundant failover trunk and a managed DID pool behind it.
SIP · TLSSIP · TLSfailoverchannels · LCRfailover routeDID / E911
On-prem PBX
Asterisk · FreePBX
Hosted PBX
cloud · managed
SIP trunk
concurrent-call channels
Failover trunk
redundant · standby
Carrier / PSTN
least-cost routing
DID pool
numbers · E911
channel sizing · DID management · least-cost routing · E911 · fraud controls
◯ AVAGOsizes, integrates & manages the trunk
What we do

Concurrent-call channels, from your PBX to the PSTN.

A SIP trunk is a pool of concurrent-call channels that carries voice between your PBX — on-prem Asterisk or FreePBX, or a hosted platform — and the carrier network that reaches the PSTN. We size the trunk to your real call volume, provision and route your DIDs, and stand up a redundant failover path so a single carrier or circuit issue doesn’t drop your phones.

The trunk itself is delivered through partner carriers — we’re able to quote and integrate with the platforms we’re partnered with — but the engineering around it is ours: least-cost routing, E911, codec selection, and toll-fraud controls. One team owns the trunk, so when a call fails there’s someone who reads the SIP trace.

Signalling over SIP with TLS; media over RTP or encrypted SRTP.
Channel sizing tuned to your busy-hour concurrency, not a flat guess.
Redundant failover trunk and routing, tested rather than assumed.
DID pool, E911, and fraud guardrails managed as part of the engagement.
What we deliver

The engineering around the trunk.

Channel & trunk sizing

We size concurrent-call channels to your real peak — not a guess — so you're not paying for idle capacity or blocking calls at busy hour.

DID management

We provision, group, and route your direct-inward-dial numbers — mains, departments, and DID blocks mapped to the right endpoints.

Redundancy & failover

A standby trunk and failover routing so a carrier or circuit blip reroutes calls instead of dropping them — tested, not assumed.

Least-cost routing

Outbound routing rules that pick the sensible path per destination, with the carrier relationship handled on your behalf.

E911

Emergency calling configured with the right dispatchable location, so a 911 call lands where it should.

Fraud controls

Toll-fraud guardrails — international dialing limits, rate anomalies, and registration hardening — to keep a compromised extension from running up a bill.

Codec selection

Codec choices matched to your bandwidth and quality needs, so voice stays clean across the trunk without wasting transport.

Problems we solve

When a trunk is the right move.

You've outgrown analog or PRI lines and want concurrent-call channels you can size up and down.
Your PBX works, but the carrier side is a black box — nobody owns the trunk when a call fails.
You need a failover path so a single carrier or circuit issue doesn't take your phones down.
DIDs and E911 have drifted out of sync with how your offices and teams are actually laid out.
You've seen toll-fraud attempts and want real guardrails on international and after-hours dialing.
Related

Often paired with SIP trunking.

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Start an engagement

Ready to put a trunk behind your PBX that someone actually owns?

No SDR, no discovery-call gauntlet. A senior practitioner personally reviews every submission and replies within one business day.

Channel & trunk sizing
DID management & E911
Redundancy, failover & least-cost routing
Fraud controls & codec selection
Direct contact
Use the contact form
(202) 903-9000

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