In short
- Protocols: SMPP, REST and SOAP.
- When SMPP fits: sustained high-volume SMS, or systems built around telecom protocols.
- Network access: whitelisted IP addresses or a VPN connection.
- Delivery receipts: one for each message.
- Account controls: fraud protection, country blocking and spending limits.
- Pricing: quoted for your volume and traffic type.
SMPP or REST: which connection fits your traffic
Both connect your systems to the same platform. The difference is how messages travel.
| SMPP | REST API | |
|---|---|---|
| How it works | One long-running session; your system sends and receives over the open connection | A separate HTTPS request for each message or batch |
| Typical sender | High, sustained volume: notifications, alerts, OTP at scale, campaigns | Application traffic: sign-up codes, order updates, events from your app |
| Your team needs | Experience with telecom protocols, or an SMPP client library | Standard web development skills |
If you are not sure, start from your volume and from what your system already supports. You can start on REST and discuss moving to SMPP as your volume grows.
Read the full SMPP vs REST comparison
How an SMPP connection works
SMPP (Short Message Peer-to-Peer) is an open industry protocol for exchanging SMS between an application and a message centre. The terms below come from the SMPP v3.4 specification and are the ones your engineers will see in any SMPP client.
| Term | What it means for your integration |
|---|---|
| Bind | Your system opens a session and identifies itself with a system ID and password |
| Transmitter bind | The session sends messages only |
| Receiver bind | The session receives only, such as delivery receipts |
| Transceiver bind | The session sends and receives over one connection |
| submit_sm | The operation your system uses to send a message |
| deliver_sm | The operation that brings messages to your system, including delivery receipts |
| enquire_link | A regular check that the session is still alive, so a broken connection is noticed and reopened |
| Window | How many requests your system may send before earlier ones are acknowledged; set by the provider |
What you get from Digital Connect as your SMPP provider
- SMPP alongside REST and SOAP. SMPP is one of three connection options, with REST for application traffic and SOAP where an existing business system needs it.
- Restricted network access. Your systems connect from IP addresses on your whitelist, or over a VPN connection.
- A delivery receipt for each message.
- Fraud protection, country blocking and spending limits on your account, agreed during onboarding.
- Sender name registration. Interkey registers your sender names with the operators through CST's central bulk-SMS system during onboarding.
- CST permit. Interkey holds CST's permit to provide short message services (SMS).
- Arabic and English messages. Arabic text is sent in Unicode (UCS-2), with 70 characters in one segment and 67 in each part of a longer message; English text in GSM-7 fits 160, or 153 per part.
- Support from Interkey's team in Riyadh, in Arabic and English.
In 2004 Interkey acquired Saudi Bells, a value-added and SMS services company.
What to settle before go-live
Agree these points with us in writing during technical onboarding. Each one affects how your SMPP client software is configured.
- SMPP version your client will use.
- Bind type: transmitter and receiver sessions, or transceiver.
- Credentials: a system ID and password for each environment, test and production.
- Network access: the IP addresses to whitelist, or the VPN details.
- Sending rate and window size your client should use.
- Delivery receipts: how they are returned on your bind and how your system matches them to sent messages.
- Arabic and long messages: Unicode encoding and how multi-part messages are joined.
- Sender names to register, by brand or department.
- enquire_link interval and reconnect behaviour.
- Country list and spending limit for the account.
- A test plan: sample traffic in Arabic and English, checked on real phones before full volume.
Who SMPP suits
SMPP suits organisations that send their own messages in volume from systems built for it, for example:
- Banks and fintech: OTP and account alerts at high volume.
- Retail and e-commerce: order updates, delivery notices and campaigns.
- Utilities and service providers: service updates and mass notifications.
- Large enterprises with telecom-adjacent systems that already speak SMPP.
When it is not a good fit: if almost all of your recipients are outside Saudi Arabia, or you send only a few hundred messages a month. For lower volume, the REST API or the web platform is simpler.
Questions about SMPP connections
Does Digital Connect support SMPP?
Yes. Digital Connect accepts SMPP, REST and SOAP connections. SMPP is intended for sustained high-volume SMS.
Is SMPP faster than REST?
SMPP keeps one session open instead of making a new request for each message, which suits sustained volume. Discuss the sending rate for your traffic with us during technical onboarding.
Can we receive delivery receipts over SMPP?
Every message has a delivery receipt. Agree with us during technical onboarding how receipts are returned on your SMPP bind.
How is the connection secured?
Access is limited to your whitelisted IP addresses or a VPN connection, and your system authenticates with its own credentials when it binds.
Can we send Arabic over SMPP?
Yes. Arabic is sent in Unicode, so one segment holds 70 characters and each part of a longer message holds 67.
How is SMPP traffic priced?
By quote, based on your volume and traffic type. OTP and promotional traffic are priced differently.