*This material is provided for reference purposes only. The information was compiled from public sources and based on the technical experience of system users. Tariffs and connection terms should be clarified directly with telecommunications operators. Oki-Toki is not a representative or agent of the companies listed below.
In Oki-Toki, the logic is configured: queues, scripts, dialer algorithms, and reporting. However, the calls themselves physically go through operator networks. Without a SIP number, the system has no connection to the outside world — it cannot receive incoming calls or place outgoing ones.
SIP number is not a separate tool, but part of the infrastructure. If a business operates in Ukraine, using a number with the +380 code is standard. Subscribers perceive it as a local call, which directly affects the Answer Rate (the percentage of answered calls). At the same time, the team’s geography does not matter: agents can be anywhere in the world as long as stable data transmission is in place.
Why the provider you choose affects the result
At the start, people often look only at the price per minute. That is a mistake, and its consequences show up as the load grows. When traffic is low, the provider’s performance is almost invisible. Problems begin when delays, dropped calls, or a “metallic” sound appear.
The connection can start to break down when launching large-scale dialer campaigns or increasing the number of simultaneous lines. At such moments, it becomes clear that the problem is neither in the software nor in the agents. The provider is the transport layer. It determines whether the call will go through, how it will sound, and whether the client will see your number correctly.
SIP telephony providers in Ukraine
SIP-GSM (SIP Hub Ukraina)
A Ukrainian provider specializing in converting mobile numbers of Ukrainian operators into SIP and replacing GSM gateways.
Technical details: connect mobile numbers Kyivstar (067, 068, 096, 097, 098), Vodafone (050, 066, 095, 099), Lifecell (063, 073, 093), Ukrainian landline numbers, as well as 0-800, “hidden” numbers (without identifiable AON), and international numbers — via SIP, without GSM gateways. It is possible to convert an already active corporate Kyivstar/Vodafone SIM card into SIP format without changing the operator and without changing the number. Unlimited multi-channel SIP trunks.
Intertelecom
A Ukrainian operator, formerly CDMA, now operating as a virtual mobile operator on a partner GSM/4G network.
Technical details: Mobile numbers in the 094 code (SIM, eSIM, or a virtual number via the IT Phone app). Direct landline numbers in nine regions: Zakarpattia, Ivano-Frankivsk, Volyn, Lviv, Rivne, Chernivtsi, Ternopil, Donetsk, and Luhansk. The “SIP Multi-Channel” service provides up to 100 simultaneous connections per number. 0-800 and number portability (MNP) are available.
Note: after the closure of CDMA, the operator’s product focus shifted to the retail segment. The terms for connecting a corporate SIP trunk should be clarified directly with the operator.
Datagroup
A national provider with a broad range of telephony products for business.
Technical details: landline numbers in the cities where it operates, numbers in the 0-891 code (a special code for IP telephony), 0-800, 0-900. Products include SIP telephony and SIP trunk. Multi-channel support is a core feature. The network covers more than 45 cities in Ukraine, including Kyiv, Lviv, Odesa, Kharkiv, Dnipro, Zaporizhzhia, Mykolaiv, Kherson, Vinnytsia, Poltava, Chernihiv, and others.
Kyivstar Business
A mobile operator with a fixed/IP telephony product line for B2B.
Technical details: Kyivstar mobile numbers (067, 068, 096, 097, 098), landline, 0-800, 0-897. The “SIP PRO” plan (launched on May 16, 2025) does not require a physical SIM. Also available are SIP Simple 50, SIP 55, SIP 170, multi-channel SIP 800 and SIP 1700 packages. Number portability (MNP) is supported.
Lifecell Business
The B2B division of the lifecell mobile operator, specializing in corporate SIP/FMC telephony.
Technical details: mobile numbers in the 063, 073, 093 codes; direct landline numbers — Kyiv, Dnipro, Odesa, Kharkiv, Zaporizhzhia. Voice traffic encryption. Multi-channel support, short internal numbering, call recording, my.lifecell.ua web interface. Number portability (MNP) is supported.
Ukrtelecom
A national fixed-line operator with separate B2B products: SIP Trunk, SIP Line, and traditional telephony.
Technical details: two key products for business — SIP Trunk (for companies with their own IP PBX, unlimited number of lines) and SIP Line (subscriber line + call forwarding, conference calling, voicemail). Landline and national numbers, 0-800. Per-second billing.
Chereda
A regional operator operating in Kyiv, Kyiv region, and Sumy. Its core business is wired internet and TV; telephony is an additional service.
Technical details: analog, digital, and IP telephony lines. For customers needing from 10 lines, a solution with digital streams is offered. SIP telephony is positioned for companies with a high volume of domestic and international calls; channels can be added without replacing equipment.
Phonet
A Ukrainian telecommunications operator (LLC “PHONET”) providing SIP numbers and IP telephony services for business.
Technical details: landline numbers in most major cities — Kyiv, Kharkiv, Odesa, Dnipro, Lviv, Zaporizhzhia, Vinnytsia, Chernihiv, and others; mobile numbers through partnerships with Ukrainian operators; 0-800; international numbers in 180+ countries. Multi-channel numbers. Porting an existing number into SIP is supported; exception — Ukrtelecom numbers, for which only call forwarding is available.
International providers
Lexicall (Lexico Telecom)
An international wholesale VoIP provider of voice termination, SMS, and DID, focused on call centers and business traffic.
Technical details: SIP trunk with A–Z termination in several quality classes. Direct inward dialing numbers (DID) in 150+ countries, including Ukraine. Detailed information by Ukrainian cities and tariffs is available only in the personal account.
Zadarma
An international VoIP provider with numbering capacity in 110+ countries.
Technical details: SIP trunk with authorization by IP or login/password. Ukrainian numbers: mobile +380 91 (with SMS receiving), Kyiv landline +380 44, national VoIP +380 89, national +380 63/93 — the number is issued after identity and address verification. Number portability (MNP) in 40 countries.
What to clarify in advance (Technical checklist)
To avoid reworking settings during operations, it is worth asking the provider a few questions before paying the invoice. These parameters directly affect system stability under load.
- Number transmission format In what format does the provider pass the client’s number? For Oki-Toki, the standard is the international E.164 format (for example, +380…). If the provider uses other prefixes, additional number conversion rules will need to be configured.
- Authorization type Is login/password registration used, or static IP authorization (SIP trunk)? For a stable call center, trunks are always preferable because they eliminate issues with periodic re-registration of accounts.
- Permissible load (CPS) The Calls Per Second parameter — how many call attempts per second the provider allows. If you launch a dialer for 50 agents and the provider’s limit is 2 CPS, the system will not work correctly, and calls will be rejected on the operator’s side.
- Codec support Is the G.711 codec used (alaw/ulaw)? This is the standard for transmitting sound without loss of quality. If the provider offers only G.729 (a compressed format), the audio may sound “pinched,” which reduces the quality of the conversation.
- Caller ID transmission (AON) Will your number be displayed correctly to the subscriber? It is important to clarify which SIP header carries the Caller ID (From, P-Asserted-Identity, or Remote-Party-ID). This determines whether your number will be identified as “Anonymous” or “Spam.”
- Testing before payment Does the provider offer a test balance or free minutes to check quality? This is necessary to measure latency and jitter in real-world conditions.
How to connect a number to Oki-Toki
The integration process for any of the listed operators in Oki-Toki is standardized. After receiving the provider data (server, login, password, or IP), you enter it into the system, configure routing rules, and can start working.
Multiple providers can be used in the system at the same time. A rational strategy is traffic separation:
- Incoming: received via one operator whose number has long been familiar to customers.
- Outgoing: made through another provider, where per-second billing terms for dialing are more favorable.
- Backup: it is always worth having a backup channel from another provider. In the event of an outage on the main operator’s side, switching routes in Oki-Toki takes a minute, which prevents team downtime.
Do not connect all lines at once. It is recommended to start with one number, check voice clarity, the absence of echo, and the correct recording of audio files. Only after successful load testing does it make sense to scale the project.
A SIP number is not just a formality, but the foundation of all telephony. If everything is configured correctly at this stage, the system will work predictably later on. If not, technical problems will start appearing at the worst possible moment.
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