---
title: Connect VOS3000 to TelecomsXchange
url: https://help.telecomsxchange.com/integrations/vos3000/
audience: Integrations
summary: In VOS3000, add a static SIP routing gateway for sip01.telecomsxchange.com
  port 5060 and a routing callee rewrite rule with original prefix * and target prefix
  80039#*, so 447700900123 leaves as 80039#447700900123. Authorise VOS3000's public
  IP on the TelecomsXchange account. To sell, add a static mapping gateway for IP
  174.136.44.213 tied to a billing account with your rate group.
updated: '2026-10-23'
verified_commit: 83b4ebc96d0081a25213776d5a8871bd04941125
---

# Connect VOS3000 to TelecomsXchange

> In VOS3000, add a static SIP routing gateway for sip01.telecomsxchange.com port 5060 and a routing callee rewrite rule with original prefix * and target prefix 80039#*, so 447700900123 leaves as 80039#447700900123. Authorise VOS3000's public IP on the TelecomsXchange account. To sell, add a static mapping gateway for IP 174.136.44.213 tied to a billing account with your rate group.

## VOS3000 to a purchased route

1. **Your VOS3000**: Static routing gateway, no registration
2. **TelecomsXchange** (via `80039#447700900123`): sip01, UDP 5060
3. **Seller's route**: The route you purchased

VOS3000 models carriers as **gateways**. A **routing gateway** is a destination VOS3000 sends calls to; a **mapping gateway** is a source it accepts calls from and bills to an account. TelecomsXchange is a routing gateway when you buy routes and a mapping gateway when you sell them. For every TelecomsXchange value in one place, see [Connect a SIP platform](https://help.telecomsxchange.com/integrations/connect-sip-platforms/).

!!! warning
    TelecomsXchange does not accept SIP REGISTER. Set the routing gateway's **Gateway type** to **Static**, never **Registration**, and don't add an entry in **Registration management** for TelecomsXchange. VOS3000 is recognised by its **source IP**.

## Before you start

- A [SIP account](https://help.telecomsxchange.com/buyers/create-your-first-account/) on TelecomsXchange with VOS3000's public signalling IP, for example `203.0.113.10`. Add other VOS3000 servers under **Edit Account → (Additional: n) → Add New IP**.
- A [purchased route](https://help.telecomsxchange.com/buyers/find-and-buy-routes/) and its tech prefix from **My Interconnections**, for example `80039#`. In this guide, `TECH_PREFIX` stands for that value.
- Access to the VOS3000 client (the desktop management console) with rights to **Operation management**.
- To sell: a [route](https://help.telecomsxchange.com/sellers/add-your-first-route/) with **IP Address:Port** set to VOS3000, for example `203.0.113.10:5060`, and the values in [Interconnect Info](https://help.telecomsxchange.com/sellers/interconnect-info/).

## How do I send calls to TelecomsXchange?

1. Open **Navigation → Operation management → Gateway operation → Routing gateway** and add a gateway, one per purchased route:
    - **Gateway name**: for example `TCXC-80039-UK`. For a static gateway it only has to be unique.
    - **Gateway prefix**: the destination prefixes this route covers, separated by commas, for example `44`. Leave it empty if you select the gateway by routing groups instead.
2. Open the gateway's **Additional settings → Normal** and set:
    - **Gateway type**: **Static** (no registration).
    - **Protocol**: **SIP**.
    - **Ip**: `174.136.44.213`, which `sip01.telecomsxchange.com` resolves to. Recent releases also accept the host name.
    - **Signaling port**: `5060`.
    - **Media proxy**: **Auto**, or **On** if your customers sit behind NAT.
3. Open **Additional settings → Routing prefix** and add a **Routing callee rewrite rule**:

| Original prefix | Target prefix | Number in | Number out |
|---|---|---|---|
| `*` | `80039#*` | `447700900123` | `80039#447700900123` |

The `*` original prefix matches every number, and `*` in the target keeps the number after the added prefix. Replace `80039#` with your `TECH_PREFIX`.

4. Make sure the number reaches the routing gateway in E.164 format, without `+` or `00`. If your customers dial `00`, strip it on their mapping gateway's callee rewrite rule (original prefix `00`, target prefix empty), or add a second rule here: original `00`, target `80039#`.
5. Leave SIP OPTIONS keepalive off for this gateway. TelecomsXchange answers OPTIONS only within a call.
6. Set **Routing clearing account** to the account that tracks your TelecomsXchange cost, with a rate group built from the route's rates (see below).

**Digest variant.** VOS3000 static routing gateways are normally authenticated by IP, and that is the setup we recommend. If you have to send from an IP that isn't on the account, add the IP under **Additional Allowed IPs** instead; the digest fields VOS3000 offers on routing gateways vary by release, so check yours (**Additional settings → Protocol → SIP → Authentication user**) before relying on them.

!!! tip
    One routing gateway per tech prefix lets VOS3000 sort your TelecomsXchange routes by priority or cost. To let TelecomsXchange choose instead, add a single gateway whose rewrite target is a [routing group](https://help.telecomsxchange.com/buyers/routing-groups-and-route-testing/) prefix, for example `444101#*`.

### How do I bill the cost?

On TelecomsXchange, open **Accounts → Edit Account** and download the route's rates from **Purchased Routes**. VOS3000 has no direct import for the TelecomsXchange formats, so take the **Default** file and load its prefixes and rates into a rate group in **Rate group management**. Assign that rate group to the clearing account set on the routing gateway; VOS3000's clearing reports then show your cost per gateway, and **Lowest profit rate limit** can stop a route being used below a margin.

## How do I receive calls from TelecomsXchange?

When you sell a route, TelecomsXchange is your customer. Its calls come from `174.136.44.213` over UDP, from source ports 5060 to 5072, with the number in E.164 format such as `14165551234`.

1. Allow `174.136.44.213` on your firewall for SIP (UDP) and your media port range.
2. Create a billing account for TelecomsXchange in **Account management**, with the rate group you sell at.
3. Open **Navigation → Operation management → Gateway operation → Mapping gateway** and add a gateway:
    - **Gateway name**: for example `TCXC-IN`.
    - **Account id**: the billing account from step 2.
4. In its **Additional settings → Normal**, set **Gateway type** to **Static** and **Ip** to `174.136.44.213`. VOS3000 matches calls by source IP; because TelecomsXchange sends from several source ports, use **Call authentication mode: IP**, not **IP Address and Port**.
5. Set which routing gateways this mapping gateway may use (**Routing gateway group**, or **Routing gateway name** allow list).
6. If your TelecomsXchange route adds an **Outgoing Prefix** (**Edit Route → Outgoing Number Translation Parameters**), remove it with the mapping gateway's callee rewrite rule, for example original prefix `77#`, target prefix empty.

!!! warning
    If you also buy from TelecomsXchange, the same IP, `174.136.44.213`, is both a routing gateway and a mapping gateway. That is normal in VOS3000: the routing gateway is used for calls you send, the mapping gateway for calls you receive. Don't give the mapping gateway permission to route back to the TelecomsXchange routing gateway, or a misrouted call can loop.

## How do I receive calls on numbers I bought?

Set the number's **SIP Endpoint (Primary)** in **DID Settings** on TelecomsXchange to VOS3000, for example `sip:14165551234@203.0.113.10:5060`. The call arrives from `174.136.44.213` and is matched by the mapping gateway above. Route the number to the phone or gateway that should answer it; for example, register the number as a phone in VOS3000 or add a routing gateway whose **Gateway prefix** is `14165551234`.

## How do I test it?

1. Place a call from a test mapping gateway or phone to a number covered by the route.
2. Watch it in **Operation management → Current call**, then open the CDR (**Data query → CDR**) to see the routing gateway used, the callee after rewrite (`80039#447700900123`) and the end reason.
3. On the VOS3000 server shell, `sngrep port 5060` or `tcpdump -n -i any udp port 5060` shows the INVITE and the reply from sip01.
4. On TelecomsXchange, watch the call in **Live Calls** and find its SIP code in **Logs → CDR (Voice)**.

## What if something goes wrong?

| You see | What to do |
|---|---|
| 401 or 407, then the call fails | VOS3000's source IP isn't authorised, so TelecomsXchange challenges for a login. Add the IP that actually sends (check the server's public NAT IP) to **IP Address** or **Additional Allowed IPs** on **Edit Account**. |
| 403 Forbidden | VOS3000's public IP isn't authorised and no credentials were sent, or the account is blocked or out of balance. |
| 404 Not Found | Missing or wrong tech prefix, or `00` left in the number. Check the **Routing callee rewrite rule** and the callee after rewrite in the CDR. |
| 408 Request Timeout | No reply from sip01. Check the gateway **Ip** and **Signaling port**, the **Local ip** VOS3000 sends from, and outbound UDP 5060. |
| 503 Service Unavailable | The route is blocked or failed on the seller's side. Check **My Interconnections**, and give the call a second routing gateway to fail over to. |
| One-way or no audio | VOS3000 advertises a private IP, or RTP is blocked. Set **Media proxy** to **On** for NAT customers, and open the media port range on the firewall. |
| Inbound calls rejected | No mapping gateway matches `174.136.44.213`, or it is set to **Dynamic**. Check **Gateway type: Static**, the **Ip** field and the firewall. |
| Inbound call rejected for no route or no rate | The mapping gateway's account rate group, or its allowed routing gateways, don't cover the E.164 destination. |

## References

- [VOS3000 manual (V2.1.8): Routing Gateway, Mapping Gateway, Rewrite Rule, Registration Management](https://www.vos3000.io/downloads/VOS3000_manual_8.0.pdf)
- [VOS3000 knowledge hub: vendor failover with gateway prefixes](https://www.vos3000.com/blog/vos3000-vendor-failover/)

## Frequently asked questions

**Q: Can VOS3000 register to TelecomsXchange?**

A: No. TelecomsXchange is peering only and does not accept REGISTER. Set the routing gateway's Gateway type to Static, not Registration, and authorise VOS3000's public IP on the TelecomsXchange account.

**Q: Where does the tech prefix go in VOS3000?**

A: In the routing gateway's Routing callee rewrite rule: original prefix * and target prefix 80039#*. That adds 80039# in front of every number sent through the gateway. Use one routing gateway per purchased route.

**Q: What is the difference between a routing gateway and a mapping gateway?**

A: A routing gateway is where VOS3000 sends calls, so TelecomsXchange is a routing gateway when you buy. A mapping gateway is where calls come from, so TelecomsXchange is a mapping gateway, IP 174.136.44.213, when you sell.

**Q: Can I import TelecomsXchange rates into VOS3000?**

A: Edit Account offers each purchased route's rates in Default, Cloud Softswitch and Sippy formats. Convert the Default file into a VOS3000 rate group and assign it to the routing gateway's clearing account to track cost.