What Is a Backconnect Proxy?
A backconnect proxy is one shared gateway, a host and port, that forwards each of your connections to an exit IP chosen from a provider's network. You keep one host and port in your tool while the outgoing IP changes per request or per session. Most residential and mobile pool products work this way; a dedicated line does not.
In brief
- Backconnect is industry shorthand, not a standard. Technically the gateway is an HTTP or SOCKS5 proxy that relays to another hop.
- The website sees only the exit IP. The gateway address never reaches it.
- Location, session and rotation are set through parameters in the username, in each provider's own format.
- You do not choose or see the exit device, and other customers may have used the same exit before you.
- Coronium sells dedicated lines, not a backconnect pool: you connect to your own device, and you decide when its IP changes.
Gateway and exits
Follow one request. Your tool opens a connection to the gateway, for example pr.oxylabs.io:7777 in Oxylabs' session control examples. For an HTTPS site, the tool sends an HTTP CONNECT request, the method defined in RFC 9110, section 9.3.6, asking the proxy to open a tunnel to the destination. With SOCKS5, the tool sends the destination in the request format of RFC 1928.
The provider's gateway then hands the connection to an exit: a server, a home connection or a mobile device somewhere in its network. The exit opens the connection to the website. The website sees the exit's IP address and nothing about the gateway.
The word "backconnect" comes from that inside step, where exits connect back to the provider's infrastructure so the gateway can use them. Neither RFC uses the term. For your tool there is nothing special about it: it is configured exactly like any other HTTP or SOCKS5 proxy.
Session parameters
Because every customer shares one gateway address, the instructions travel in the username. Each provider has its own grammar. Three documented examples, read October 30, 2026:
Oxylabs customer-USERNAME-cc-DE-sessid-abcd1234-sesstime-30
Bright Data brd-customer-<customer_id>-zone-<zone_name>-session-<session_id>
Decodo user-USERNAME-session-<id>-sessionduration-30
The Oxylabs string pins country (cc-DE), a session ID and a 30-minute session time. Bright Data's rotation page adds that changing targeting parameters between requests drops the session even with the same ID. Decodo's session types page accepts durations from 1 to 1440 minutes.
Common mistakes with these strings:
- A typo in a parameter name is often treated as part of the username, which fails authentication with a 407 instead of an obvious error.
- Special characters in a session ID break some providers' parsers. Bright Data asks for letters and numbers only.
- Tools that split the username at
-or:mangle the string. Paste it into a field marked username, not into a combined proxy line, when the tool offers both.
What a gateway hides from you
A gateway is convenient because it hides the network behind it. That is also its main limit:
- You do not pick the device. You ask for a country or city; the provider decides which exit you get.
- You do not see its history. Other customers may have used the same exit minutes before you, for anything their terms allowed.
- The exit can vanish. On home and mobile pools, the device may disconnect mid-session. Providers document early rotation for this reason.
- You depend on the provider's sourcing. Residential and mobile exits are someone's device and connection. How the provider got permission to use them matters; the residential proxy guide covers what regulators have found.
None of this makes a gateway wrong. It makes it a good fit for broad, stateless work and a weaker fit for long-lived accounts.
Questions to ask a gateway provider
Because so much is hidden behind the gateway, ask before you buy:
- Where do the exits come from? An opt-in program with clear consent, devices the provider operates itself, or software bundled into third-party apps. The answer says a lot about the exits' history.
- What kind of exits are they? Data center, home broadband or mobile carrier, and whether you can choose.
- How long can a session last, and what ends it? The documented maximum, the idle limit and what happens when an exit drops.
- How is it billed? Per gigabyte, per port or per address, and whether failed requests count.
- Which protocols? HTTP CONNECT, SOCKS5 with remote DNS, or both.
A provider that cannot answer the first question clearly is asking you to accept its exits' history without seeing it.
Backconnect vs dedicated line
| Question | Gateway pool | Dedicated line |
|---|---|---|
| What you configure | One shared gateway host and port | Your line's own host and ports |
| Which exit you get | Chosen by the provider per session | Always your device |
| Who else uses the exit | Other customers, over time | No other Coronium customer |
| How the IP changes | New session ID, timer or exit dropping out | Button, API, rotation link or your timer |
| Where it fits best | Broad, stateless collection | Accounts and repeated checks |
A dedicated line removes the gateway's selection step. On Coronium, each line is one physical device with its own SIM, rented to one customer. You connect to that line's own host, with HTTP and SOCKS5 on separate ports. The website sees the device's carrier IP, which no other Coronium customer uses.
The IP changes only when you change it: dashboard button, API call, rotation link or a timer of at least 60 seconds. Some device types rotate on request only. Data is not metered on dedicated lines, apart from Brazil lines, which carry 20 GB a month and rotate on request only.
Which to choose:
- Many short, independent requests across many locations: a gateway pool.
- A few accounts or sessions that should keep one identity for days: a dedicated line per account group.
- Checks from one country and carrier, repeated over time: a dedicated line, so changes you see come from the site, not from a different exit.
Sources and review scope
Sources reviewed October 30, 2026. Standards, vendor documents and regulator pages were read on the date above. Where a page shows commands, they were run with curl 8.7.1 and Python Requests 2.32 against a local authenticated test proxy; addresses in the output are replaced with documentation ranges. Vendor parameters change, so confirm them in the vendor documentation linked here.
Frequently asked questions
More proxy questions
Short answers first, then the detail, with the standard or vendor document behind each claim.
Related workflows
Dedicated 4G and 5G carrier lines, with live stock and prices for each country and carrier.
How long one exit IP lasts on a pool, and how to check it.
Rotation methods, timing and their trade-offs.
One device and one SIM per customer.
Where residential exits come from and how they are billed.
Short answers to common proxy questions.
Where to get a dedicated line
A Coronium mobile proxy is one physical device with its own SIM, rented to one customer. It connects over HTTP or SOCKS5, the IP changes by dashboard button, API link or timer, and data is not metered on dedicated lines. Brazil lines are the exception: 20 GB of data a month and a new IP on request only, with no timer. Stock and prices differ by country and carrier.