A static IP for your SMPP bind. Register it once.
SMS providers often accept SMPP connections only from IPs you've registered with them. When your address changes, the bind fails and messages queue up. TrueIP gives your SMPP client a dedicated IPv4 that stays the same.
Why the bind fails after an IP change.
Your gateway was sending fine. Then binds start failing or the connection drops straight after it opens, and the queue grows. The username and password haven't changed. The SMSC simply doesn't recognise the address you're connecting from any more.
SMPP runs as a long-lived TCP connection, and a lot of providers lock it to known addresses. Twilio's SMPP service accepts connections only from a predetermined set of IP addresses. Sinch restricts access to pre-registered IPs by default, and Infobip asks for the source IPs to safelist. Registering a new address usually means a support ticket, not a dashboard edit.
So any change on your side breaks sending. A cloud server that comes back with a new outbound address, an office line the ISP renumbers, or a move to a new host all have the same effect.
One thing to be clear about: this page is about SMPP only. SIP trunks for voice need UDP and incoming calls to your IP, and TrueIP carries only outgoing TCP. It can't run a SIP trunk.
Fixed IP for SMPP in three steps.
- 01
Get a dedicated IPv4
Sign up and pay online. The IP is assigned in minutes, with its own host, port, username and password.
- 02
Register it with your provider
Send the address to your SMS provider to add to their allowlist for your SMPP account.
- 03
Start a local tunnel
Run a small tunnel (below) and point your SMPP client at 127.0.0.1. Check the address with curl -x http://USER:PASS@HOST:PORT https://ifconfig.co.
A local tunnel for the bind.
Most SMPP libraries open a plain TCP socket and can't use an HTTP proxy themselves. A one-line tunnel with socat or ncat opens the connection through TrueIP, and your client connects to it locally.
- ✓ Works with any SMPP client, because it only sees a local port
- ✓ The SMSC sees your TrueIP address on the bind
- ✓ If your provider uses SMPP over TLS, set the TLS server name to the SMSC's hostname in your client
- ✓ One IP per gateway server if you run more than one
What a static IP for SMPP gives you.
One IPv4, only yours
A whole address reserved for your account and never shared, so your SMSC allowlist trusts only your traffic.
Same IP on renewal
Renew on time and the address never changes, so there's no new allowlist ticket with your provider.
Move servers freely
Rebuild or move your gateway and keep the same IP. Just start the tunnel on the new machine.
Per-IP credentials
Each IP has its own host, port, username and password, one per gateway or per provider account.
GST invoice for your ITC
Every payment comes with a GST invoice in your company's name once you add your GSTIN in the portal.
Priced per IP. IPv4 for SMPP.
None of the SMPP providers we checked say they accept IPv6, and python-smpplib only opens IPv4 sockets. Pick IPv4.
IPv4 dedicated
Pick this for SMPPThe address SMS providers expect in their allowlist. Same price per month on any term.
- Dedicated IPv4, never shared or rotated
- Per-IP host, port, user and password
- Same IP kept across renewals
- CSV export of credentials
- GST invoice on every payment
IPv6 dedicated
Locked for lifeNot for SMPP today. Useful for other services in your stack whose allowlists accept IPv6.
- Unique /128, never shared or rotated
- Per-IP host, port, user and password
- Same IP kept across renewals
- Price locked while you stay subscribed
Need IPs for a team or several servers? Same price per IP, one GST invoice.
Running SIP voice too? That needs a different kind of connection. Tell us what you need.
SMPP questions.
Will the IP ever change?
No. The address stays the same for your whole term and on every renewal. Renew before it expires and your provider never needs a new allowlist entry.
Do I get a GST invoice?
Yes, on every payment. IPv4 is ₹200 + 18% GST, so ₹236 a month. Add your GSTIN in the portal to get it in your company's name.
Is my data visible to you?
If your provider supports SMPP over TLS, use it, and the traffic stays encrypted end to end through TrueIP. With plain SMPP the connection itself isn't encrypted, as with any network path. We don't log or store message content either way.
IPv4 or IPv6 for this?
IPv4. The SMPP providers we checked don't say they accept IPv6, and common clients like python-smpplib only open IPv4 connections.
Does it work for SIP trunks?
No. SIP signalling commonly uses UDP, voice media (RTP) runs over UDP, and the provider sends calls in to your IP. TrueIP carries only outgoing TCP connections, so it can't carry SIP or voice.
Why do I need a tunnel?
Most SMPP libraries connect with a plain TCP socket and have no setting for an HTTP proxy. The tunnel opens the connection through TrueIP for them, so your client just connects to a local port.
Which SMSC port does it work with?
Any TCP port your provider uses. 2775 is the usual SMPP port, but many providers use others. Put their host and port in the tunnel command.
Guides for this setup
SMPP bind failing after an IP change? Here's what's going on
Your SMPP bind worked until your server IP changed. Why SMS providers drop the connection, how to confirm it's the IP, and how to keep one address.Why your API says "IP not whitelisted" and how to fix it for good
Your API key is fine but every call fails with "IP not whitelisted". Here's how to find the address the API sees, why it changed, and how to stop it changing.IPv4 vs IPv6 for whitelisting: which one will your platform accept?
Some allowlists take IPv6, many still want IPv4. Which platforms accept which, how to test yours in two minutes, and when ₹50 IPv6 beats ₹200 IPv4.More setups on the use cases page, or find the right IP type in 30 seconds.
A fixed IP for your SMSC. Live in minutes.
A dedicated IPv4 from Mumbai for ₹200 + GST a month. Register it once and keep it on every renewal.