International A–Z Voice Routing
Quality-constrained least-cost routing across 600+ direct routes - with per-prefix control, named routing profiles and a route-testing lab, so your traffic lands where you decide it should.
600+
Direct routes
< 2 s
Median post-dial delay
1,900+
Prefixes under management
What is International A–Z Voice Routing?
International A–Z Voice Routing is the routing layer behind Dollu's wholesale voice business, offered as a service in its own right. Instead of buying a single termination product, carriers and aggregators plug into a curated route portfolio - direct interconnects, Tier-1 partner routes and vetted wholesale supply - and control exactly how their traffic is distributed across it, prefix by prefix, tier by tier.
The engine at the centre is a least-cost router with quality constraints. Every candidate route for a prefix carries live ASR, ACD, PDD, MOS and CLI-delivery scores. LCR only ever chooses among routes that clear the thresholds you set for that destination, so a cheap route that has started to fail on Nigeria mobile or India fixed drops out of the selection automatically rather than dragging your answer rate down.
You configure routing through named profiles - for example a Premium profile for contact-centre customers, a Wholesale profile for dialler traffic and a Bypass profile for a specific bilateral partner - and assign profiles per trunk, per sub-account or per originating CLI range. Within a profile you can pin, exclude or re-weight any prefix, cap CPS and concurrent calls, and set failover order and retry behaviour on SIP response codes.
A route-testing lab, portal analytics and API access sit alongside the routing engine. Test any prefix on any candidate route before you commit traffic, download and diff rate decks, and pull routing decisions and CDRs into your own switch or BI stack. Our routing desk works with you on standing routing reviews so the portfolio keeps up with what the market is doing.
Wholesale routing: how a call finds its route.
Why choose Dollu for a–z routing.
The advantages of buying from a carrier that owns its network, interconnects and operations - rather than a reseller.
Lower blended cost without a quality tax
LCR that only picks among in-threshold routes drives cost down on every destination while keeping ASR and CLI delivery inside the limits your customers expect.
Full control, not a black box
See which route carried each call and why. Pin a route, exclude a supplier or re-weight a prefix yourself in the portal - no ticket, no waiting for a routing team.
Faster response to route changes
When a destination goes bad at 03:00, the engine has already moved traffic. You get an alert with the before-and-after KPIs rather than a customer complaint in the morning.
One portfolio, many customer segments
Serve retail-quality and wholesale customers from the same interconnect using separate profiles, each with its own route mix, margins and reporting.
Testing before commitment
Route testing with real audio capture, CLI verification and PDD measurement lets you validate a supplier or a new destination before a single production minute is at risk.
Capabilities in detail.
Everything included with International A–Z Voice Routing - the platform features, options and controls you get from day one.
- 01
Quality-constrained least-cost routing
Per-prefix cost ranking bounded by configurable ASR, ACD, PDD, MOS and CLI-delivery floors; routes falling below threshold are excluded until they recover and are re-qualified.
- 02
Routing profiles and inheritance
Create named profiles with a base tier and layered overrides; assign to trunks, sub-accounts or originating CLI ranges. Changes propagate instantly across all assigned trunks.
- 03
Per-prefix controls
Pin, exclude, weight and order routes for any of 1,900+ prefixes; set prefix-level CPS, concurrent-call caps, maximum PDD and hunt depth; apply time-of-day and day-of-week rules.
- 04
Failover and retry logic
Configurable hunt across up to eight routes with retry on selectable SIP response codes, ring-no-answer timers and cause-code mapping so your switch sees consistent behaviour.
- 05
Route-testing lab
Generate test calls to any prefix on any candidate route, capture audio, verify CLI on receiving numbers in 60+ countries, and log ASR, PDD and codec negotiation for each attempt.
- 06
Rate-deck automation
Machine-readable A–Z rate decks with effective dates, per-prefix diff against the previous deck, 7-day increase notice, and API endpoints for pulling decks into your billing system.
- 07
Routing analytics
Route-selection reports per prefix and per profile, supplier scorecards, margin per destination and traffic-shift timelines, exportable via SFTP or API.
- 08
Bilateral and bypass routing
Route specific prefixes to a bilateral partner or your own downstream supply while the rest of the A–Z stays on the Dollu portfolio, with combined reporting.
- 09
API and switch integration
REST API for profiles, prefix rules and rate decks; SIP 3xx redirect and ENUM-style routing responses for customers running their own class-4 switch.
How it works.
From first conversation to live traffic - a tracked, engineer-led onboarding with a named owner at every step.
- Step 01
Discovery
Share your destination mix, current suppliers and quality expectations. Our routing desk maps your top prefixes to the portfolio and proposes an initial tier and profile structure.
- Step 02
Build profiles
We configure your routing profiles, prefix overrides and thresholds in the portal with you. Rate decks and API credentials are issued for your billing and switch teams.
- Step 03
Test in the lab
Validate priority prefixes on candidate routes with test calls, audio capture and CLI checks. Adjust thresholds and weights before production traffic starts.
- Step 04
Route and monitor
Traffic flows under your profiles with automatic failover. Alerts fire on quality decay, route exclusion or supplier changes, with the full decision trail available.
- Step 05
Review monthly
Your routing desk contact reviews supplier scorecards, cost per destination and traffic shifts with you and tunes the portfolio as the market moves.
Premium, Standard or Wholesale.
Every destination on the Dollu rate deck is offered in up to three quality tiers. Pick per destination - or per customer - and mix them on one interconnect.
| Dimension | Premium (CLI-guaranteed) | Standard | Wholesale |
|---|---|---|---|
| CLI delivery | Guaranteed - the originating number is delivered intact to the called party | Best effort - CLI is normally delivered but not contractually guaranteed | Not guaranteed - CLI may be withheld or replaced on some routes |
| Route type | Direct operator interconnects and Tier-1 partners only | Direct and vetted partner routes, quality-steered in real time | Least-cost blended routes, swapped freely to hold the price |
| Typical ASR band | Highest | High | Variable |
| PDD | Lowest | Low | Variable - can rise on multi-hop transit |
| Best for | Contact centres, retail and enterprise traffic, OTP voice calls - anywhere the called party must see who is calling | Business traffic where quality matters and CLI is helpful but not mandatory | High-volume carrier, dialler and call-centre traffic where price per minute dominates |
| SLA | Per-destination ASR, ACD and PDD targets with service credits | Quality targets monitored and reported; credits on core availability | Core availability only; route quality is managed, not guaranteed |
| Price position | Highest | Mid | Lowest |
All three tiers ride the same SIP interconnect, portal and CDRs - the tier is chosen per destination prefix, so you can move traffic between them without a new set-up.
Who uses this and why.
Typical deployments across carriers, enterprises, platforms and contact centres.
International carriers
Outsource A–Z routing operations for non-core destinations while keeping direct control of the prefixes that matter to your own bilateral relationships.
Wholesale aggregators
Run multiple customer segments from one interconnect with profile-level route mixes, margins and reporting, and add supply depth on volatile destinations.
Class-4 switch operators
Use Dollu as an intelligent downstream with SIP redirect or ENUM responses, taking our route selection while your switch keeps the customer relationship.
Contact-centre carriers
Guarantee CLI and ASR on outbound campaigns to specific countries by pinning premium routes for those prefixes while the long tail rides LCR.
OTT and app operators
Balance margin and quality per destination for app-to-PSTN calling, with automatic exclusion of routes that start to fail before subscribers notice.
Technical & commercial specifications.
Key parameters at a glance. Ask us for the full service description and SLA document.
| Portfolio | 600+ direct routes; Tier-1 and vetted wholesale supply; 230+ destinations |
|---|---|
| Routing engine | Quality-constrained LCR; up to 8-route hunt; SIP cause-code retry |
| Quality inputs | ASR, ACD, PDD, MOS, CLI delivery, sampled every 5 minutes per route |
| Granularity | 1,900+ prefixes; profile, trunk, sub-account and CLI-range scope |
| Controls | Pin, exclude, weight, CPS, concurrent calls, max PDD, time-of-day rules |
| Testing | Test-call generator, audio capture, CLI verification in 60+ countries |
| Rate decks | Effective-dated A–Z decks; per-prefix diff; 7-day increase notice; API |
| Integration | REST API, SIP 3xx redirect, ENUM-style responses, SFTP export |
| Reporting | Route-selection logs, supplier scorecards, margin per destination |
| Support | Dedicated routing desk; 24×7 NOC; monthly portfolio review |
How Voice & Wholesale is priced.
Wholesale voice is priced from an A–Z rate deck: a rate per destination and breakout for each quality tier, billed on connected seconds. There are no setup or port fees on SIP interconnects.
We publish the model, not a public rate card - actual rates depend on destination, route class, volume and regulatory cost. See how every Dollu service is priced.
- A–Z rate deck in USD, EUR, GBP or INR
- Premium (CLI), Standard and Wholesale tiers per destination
- 1/1 billing on most destinations; 60/60 flagged on the deck
- Volume tiers from 1M minutes a month; bilateral and swap for carriers
- Rate increases with at least 7 days’ notice; decreases immediate
- Billing
- Prepaid (online top-up, auto-recharge) or postpaid net-15/30 after credit review; per-second increments
- Commitment
- None - month-to-month usage; optional volume commitments unlock better tiers
230+ destinations, A–Z.
Every country on the rate deck, in Premium, Standard and Wholesale tiers where the market supports them - over 600 direct carrier interconnects and Tier-1 partners. Country guides cover the destinations with the most traffic.
A–Z Routing - your questions answered.
The questions customers and carriers ask us most often before they interconnect. If yours is not here, our team answers within one business day.
Still have a question?
Ask our solutions teamRelated services.
Services customers commonly combine with International A–Z Voice Routing.
See how your top 50 prefixes would route.
Send us your destination mix and current KPIs and our routing desk will return a proposed profile, expected quality bands and indicative cost per prefix.
