How a Logistics Operator Cut International Call Spend by 38%
38% lower international call spend
About this case study: results are from a real Salamtalk deployment. The customer’s name is a pseudonym and their logo is withheld under a confidentiality agreement. The metrics below are reported as measured.
The situation
FleetLink International runs dispatch centers in multiple countries, coordinating drivers and shipments across borders. The company had built its dial plan and call flows on an existing Asterisk/FreePBX setup over several years, and had no interest in replacing a system its dispatch teams already knew well. The problem was the trunking behind it.
- International call costs were high and unpredictable. Calls from dispatch centers to drivers abroad were routed through a single international carrier with limited rate flexibility.
- Driver callbacks used foreign numbers. Drivers in each country were calling dispatch on numbers that looked foreign to them, which depressed answer rates and slowed callbacks.
- Channel capacity was fixed. Dispatch peaks around shift changes and shipment deadlines meant the fixed channel count was sometimes a bottleneck, and sometimes idle capacity the rest of the day.
What they needed
FleetLink wanted lower international call costs and local numbers in each driver market, without touching the Asterisk/FreePBX dial plans and call flows dispatch teams already relied on. Channel capacity needed to flex with dispatch peaks rather than being fixed. Cost control through least-cost routing across destinations was a specific requirement, given the volume and spread of FleetLink’s international calling.
What we deployed
| Requirement | Implementation |
|---|---|
| PBX interop | Salamtalk SIP trunks connected directly to FleetLink’s existing Asterisk/FreePBX setup; no PBX replacement |
| International calling | Least-cost routing (LCR) applied across FleetLink’s international call destinations |
| Local presence | Local DIDs issued in each country with a dispatch center or significant driver population |
| Capacity | Elastic channel bursting to absorb shift-change and deadline-driven dispatch peaks |
| Encryption | TLS 1.3 signalling, SRTP media on all trunk traffic |
| Reach | Numbers available across Salamtalk’s coverage in 100+ countries |
Only the trunks changed. FleetLink’s dispatch teams kept their existing extensions, call flows, and IVR menus inside Asterisk and FreePBX; Salamtalk’s SIP trunking replaced the carrier connection behind it.
How the migration ran
- Audited FleetLink’s existing trunk configuration, call volumes by destination, and channel usage patterns across dispatch centers.
- Provisioned Salamtalk SIP trunks alongside the existing carrier trunks, so both ran in parallel during testing.
- Issued local DIDs in each target driver market and tested inbound driver callback flows before cutover.
- Moved outbound international traffic to the new trunks destination by destination, monitoring call quality and routing cost at each step.
- Decommissioned the legacy carrier trunks once all dispatch centers were confirmed running cleanly on the new trunks.
Channel bursting was tested specifically against a known shift-change peak before go-live, since that was the scenario where the fixed-channel setup had previously caused blocked calls.
The results
- 38% lower international call spend, driven by least-cost routing across FleetLink’s calling destinations
- Local DIDs issued in each driver market, improving answer rates on dispatch-to-driver callbacks
- Elastic channel capacity absorbing shift-change and deadline peaks without blocked calls
- Existing Asterisk/FreePBX dial plans and call flows kept entirely intact
The cost reduction came from routing international traffic more efficiently by destination rather than through a single fixed-rate carrier path. FleetLink’s dispatch teams reported that local DIDs noticeably improved how quickly drivers picked up callbacks, though this was observed qualitatively rather than tracked as a formal metric.
What was harder than expected
Matching least-cost routing to FleetLink’s actual traffic pattern took more tuning than expected. FleetLink’s calling was concentrated in a smaller number of countries than typical LCR configurations assume, so the routing had to be tuned specifically to that concentration rather than applied as a generic international ruleset. Early routing choices saved less than projected until this was adjusted.
Parallel-running two trunk providers during cutover added temporary complexity to the dial plan. Running old and new trunks side by side for testing meant FreePBX’s outbound routing rules had to temporarily account for both paths, which is more configuration than a straight replacement would have needed. FleetLink’s telecom administrator judged the added safety of a gradual cutover worth the temporary complexity, given how central dispatch calling is to daily operations.
Next steps: see SIP trunking for the trunk capability, global numbers for local DIDs by country, or talk to our team about a trunk-only migration plan.