Most wholesale VoIP buying decisions are made in the first fifteen minutes of a sales call, when a provider slides a rate deck across the table and the lowest number wins. It's an understandable shortcut — rate decks are easy to compare and everything else is hard — but it's also the reason so many carriers and resellers end up switching providers eighteen months later, after discovering that the cheap route they picked drops one call in three to the country that matters most. This is a working checklist for doing the comparison properly, before any volume is committed.
Start With What You're Actually Sending
The best provider for a call center is rarely the best provider for an OTP delivery platform, and neither is ideal for a reseller with a mixed customer base. Before evaluating anyone, write down your traffic profile: your top ten destinations by volume, your average call duration, whether the recipient needs to see a recognizable caller ID, and how sensitive your customers are to a bad week of connection rates. Every later decision — route type, billing terms, redundancy expectations — flows from that one page of notes.
Match the Route Class to the Job
International termination usually comes in three flavors, and the labels matter more than the marketing around them:
- CLI routes deliver the caller's real number to the destination. They cost more and connect more often, which is why they suit anything a human decides whether to answer — sales calls, support callbacks, appointment reminders.
- Non-CLI routes make no promise about what number appears. They're cheaper and perfectly reasonable for notification traffic, OTP delivery, or anywhere the recipient isn't choosing whether to pick up based on the screen.
- CC (call-center) routes are provisioned for the odd shape of dialer traffic: huge attempt volume, short durations, and an ASR that would look alarming on a normal business line but is expected here.
The expensive mistake is using one class for everything. Putting customer-facing calls on a Non-CLI route to save a fraction of a cent usually costs far more in unanswered calls than it saves on the invoice. We keep our own CLI and Non-CLI pricing on separate pages for exactly this reason — they're different products, not two prices for the same thing.
Ask for Quality Numbers by Destination
ASR and PDD are the two figures that reveal what a route is really doing. ASR — the share of attempts that get answered — for solid CLI routes into major markets commonly lands somewhere between 60 and 80 percent, with mobile destinations running lower than landlines. PDD — the silence between dialing and the first ring — should stay comfortably under a handful of seconds; long delays make callers hang up before the call has a chance.
The critical word here is by destination. A blended network-wide average can look excellent while three of your top five countries are quietly underperforming. A provider who won't share destination-level numbers, or who can't show live monitoring, is telling you something about how closely they watch their own network.
Check Coverage Depth, Not Just Country Count
"A-Z termination" means the provider can route to essentially anywhere, which is convenient, but the phrase hides a lot. Ask how coverage splits between mobile and landline in the specific countries you care about, how the provider handles hard-to-reach destinations, and whether premium or satellite prefixes carry surcharges that don't appear in the headline rate. Gaps in coverage force you into a second provider relationship, which means a second contract, second rate deck, and a second reconciliation headache every month.
Read the Billing Terms Like a Contract, Because They Are One
Two decks with the same per-minute price can produce very different invoices. The billing increment — whether a call is rounded to the second, to six-second blocks, or to whole minutes — quietly rewrites the effective rate, especially on short calls. Look also for minimum call durations, rounding conventions, and whether the provider applies false-answer supervision, which bills calls that technically connected without anyone really answering. Our own rate tables show the initial and incremental billing for every destination right next to the price, because a rate without its increment is only half a number.
Understand How You'll Actually Connect
There are two broad approaches. Direct SIP peering — traffic exchanged over private IP links at a shared point of presence — gives you the shortest path and the most control, but expects some technical coordination: IP whitelisting, codec agreement, and someone who can talk to the provider's network team. Managed trunking through an aggregator trades some margin for simplicity, with the provider handling routing, failover, and rate management. Neither is better in the abstract; a reseller without network engineers is usually well served by the managed model, while a carrier with its own switching team often prefers direct peering.
On codecs, G.711 delivers the best audio at higher bandwidth, while G.729 compresses aggressively and saves bandwidth on high-volume routes where fidelity is secondary. Any serious provider supports both and negotiates them at call setup.
Take Fraud Seriously Before It Takes You Seriously
International revenue share fraud is the nightmare scenario: compromised accounts generate enormous volumes of calls to premium destinations over a weekend, and the bill arrives Monday. Ask what your provider does about it — real-time anomaly detection, per-destination spending caps, the ability to block a country instantly, and a fraud contact who actually answers at night. A provider with no answer to this question is asking you to carry a risk they're better placed to manage.
Redundancy, SLAs, and the Honest Meaning of "99.9%"
A 99.9 percent uptime figure allows roughly nine hours of downtime a year — that's not nothing, and it only matters if there are contractual credits attached. More revealing is the architecture behind the promise: multiple geographically separate points of presence can route around a failure, whereas a single-site provider is one incident away from a very bad day no matter what the SLA says. Ask where the redundancy actually lives, and how quickly traffic reroutes when a path degrades. We publish more about our approach on the network page.
Judge the Onboarding, Because It Predicts the Relationship
How a provider handles the first week tells you how they'll handle the fiftieth. Are test credentials issued the same day? Is provisioning done in hours or weeks? Is there documentation and an API, or a chain of emails? Providers who automate rate updates, CDR access, and trunk provisioning are structurally better equipped to scale with you than those who run everything by hand. If you'd like to see what that first week looks like, you can request test credentials and check real quality on your own top destinations before committing anything.
A Short Version to Keep Next to the Rate Deck
- Write down your traffic profile first — destinations, duration, caller ID needs.
- Match CLI, Non-CLI and CC routes to specific traffic instead of buying one class for everything.
- Get ASR and PDD by destination, not as a network average.
- Confirm mobile versus landline coverage and any hidden surcharges.
- Compare billing increments before comparing prices.
- Choose direct peering or managed trunking based on your team, not on habit.
- Ask what happens during a fraud event, and who picks up the phone.
- Test on live traffic before moving volume.
Frequently Asked Questions
What's the real difference between CLI and Non-CLI routes? CLI routes pass the caller's actual number through to the recipient, which improves answer rates and satisfies rules in some markets. Non-CLI routes offer no such guarantee and cost less, making them better suited to bulk or automated traffic where caller identity doesn't affect the outcome.
How do I compare two rate decks fairly? Re-price a sample of your real call records under each deck's billing increment and surcharges, then divide the total by actual talk time. The cheapest headline rate often isn't the cheapest effective rate.
Is SIP trunking the same thing as wholesale VoIP? Not quite. SIP is the connection method; wholesale VoIP is the commercial arrangement for buying voice capacity in bulk. Most wholesale traffic travels over SIP, but SIP trunking can also mean connecting an office phone system, which is a different use case.
What ASR should I expect? It varies by destination and route class, but well-run CLI routes into major markets commonly sit in the 60 to 80 percent range, with mobile lower than fixed lines. Anything persistently below 40 to 50 percent deserves a hard question.