Binds
What a bind is, the bind types, IP allowlists, countries and speed limits.
A bind is one SMPP login. Each bind has its own settings:
| Setting | Meaning |
|---|---|
system_id | The login name, for example kwacha482913. Lower-case letters and digits, up to 15 characters. Shown in the portal. |
| Password | 8 characters. Made by the portal and shown once. Never sent by email. |
| Allowed IPs | Public IP addresses or small networks allowed to connect. Up to 20. |
| Countries | The only countries this bind may send to. |
| Throughput | The most messages per second the bind may send. |
| Session limit | Optional. How many sessions may be open at the same time. |
| Credit | SMS credits left on the bind. A new bind starts at 0. |
| Status | Active or suspended. A suspended bind cannot send. |
Bind types
| Type | Command | Use it to |
|---|---|---|
| Transmitter (TX) | bind_transmitter | Send only. |
| Receiver (RX) | bind_receiver | Receive delivery receipts only. |
| Transceiver (TRX) | bind_transceiver | Send and receive on one connection. Best for most clients. |
If you use TX for sending, also open an RX session with the same system_id, or you will not get delivery receipts.
Passwords
- The password is made for you. It is 8 characters, as SMPP 3.4 allows.
- It is shown once, when the bind is made or when you choose Reset password on the Binds page. Copy it into your SMPP client straight away.
- You can reset it any time. Sessions using the old password stop working at their next bind.
IP allowlist
- Only listed addresses can reach port 2775. Connections from any other address are refused by the server firewall.
- Each entry is one public IPv4 or IPv6 address, or a network no wider than
/24(IPv4) or/48(IPv6). For example203.0.113.10or203.0.113.0/24. - Up to 20 entries per bind.
- Private, loopback and local addresses (like
10.x,192.168.xor127.0.0.1) are refused. List the address the internet sees. - If your server is behind NAT or a cloud gateway, list the gateway's public address.
- Change the list on the Binds page, under IPs. The firewall picks up changes within about a minute.
Countries
Each bind is locked to its countries inside the SMPP gateway. A message to any other country is refused in the submit_sm_resp and costs nothing. Your account manager or reseller sets the countries.
- A bind sold by a reseller covers exactly one country.
- A bind sold directly by SMS YANU can cover several countries. It has one price per SMS: the highest price of its countries.
Throughput
Each bind has a speed limit in messages per second, shown in the portal.
| Who sets it | Range | Default |
|---|---|---|
| SMS YANU staff | 1 to 500 per second | 20 |
| A reseller, for its clients | 1 to 100 per second | 10 |
If you send faster, extra messages are refused with ESME_RTHROTTLED (0x00000058). Slow down and send them again.
Good practice:
- Use a window of 10 or fewer unanswered
submit_smat a time. - Spread long sends over time instead of in bursts.
- Ask for a higher limit if you need it.