---
title: "How do I set up Groundwire with VoIP.ms?"
topic: "SIP Providers"
updated: 2026-05-09
canonical: https://acrobits.net/resources/knowledge-base/how-do-i-set-up-groundwire-with-voip-ms/
summary: "Groundwire defaults to G.711u (PCMU), which is what VoIP.ms recommends for North American calling. If you have limited bandwidth or are on cellular data, enable G.729a as a fallback. For HD calling between two Groundwire users on Wi-Fi, enable G.722."
---

# How do I set up Groundwire with VoIP.ms?

> Groundwire defaults to G.711u (PCMU), which is what VoIP.ms recommends for North American calling. If you have limited bandwidth or are on cellular data, enable G.729a as a fallback. For HD calling between two Groundwire users on Wi-Fi, enable G.722.

[**Groundwire**](/sip-client-ios-android/) ships with a built-in VoIP.ms preconfiguration, so you don't enter SIP server settings manually — pick VoIP.ms from the provider list, enter your account credentials, done. Most users are making and receiving calls inside 5 minutes. For a plain-English look at the provider itself — pricing, reliability, and how it pairs with the app — see our [VoIP.ms review](/blog/groundwire/voip-ms-review/).

## What you need

  - A VoIP.ms account with at least one DID purchased

  - A sub-account created in the VoIP.ms portal (recommended over using the main account)

  - Groundwire installed on iOS or Android

## Step 1 — Create a sub-account in VoIP.ms

  - Log into the VoIP.ms portal → **Sub Accounts → Create Sub Account**.

  - Set a username (format: 123456_yourname, where 123456 is your main account number) and a strong password.

  - Set **Auth Type** to "User/Password Authentication".

  - Set **NAT** to *Yes* (recommended — handles routing for mobile networks).

  - Enable **Encrypted SIP Traffic** if you want TLS + SRTP on the SIP signalling and media. Optional but recommended on public Wi-Fi.

  - Assign your DID to route to this sub-account under **DID Numbers → Manage DID**.

## Step 2 — Add the account in Groundwire

  - Open Groundwire → **Settings → Accounts → Add account**.

  - Search the provider list for **VoIP.ms** and select it. Groundwire pre-fills the SIP server and ports for you.

  - Pick the regional server closest to you (e.g. denver1.voip.ms, atlanta1.voip.ms, london.voip.ms) — match this to the POP you selected in the VoIP.ms portal.

  - Enter the sub-account username (e.g. 123456_yourname) and password.

  - Save. The registration indicator should turn green within seconds.

## Step 3 — Codecs and transport

Groundwire defaults to **G.711u (PCMU)**, which is what VoIP.ms recommends for North American calling. If you have limited bandwidth or are on cellular data, enable G.729a as a fallback. For HD calling between two Groundwire users on Wi-Fi, enable G.722.

Transport: UDP on port 5060 by default. Switch to TLS on port 5061 if you enabled "Encrypted SIP Traffic" in the VoIP.ms portal.

## Why Groundwire is the right softphone for VoIP.ms

VoIP.ms [recommends Acrobits](https://blog.voip.ms/blog/which-softphone-is-the-best-for-you/) alongside Bria, Zoiper, Linphone, and Grandstream Wave. The reason most VoIP.ms users settle on Groundwire specifically:

  - **Built-in VoIP.ms preconfig** — no manual SIP server entry.

  - **SIPIS** (Acrobits' SIP push server) — your phone rings even when Groundwire is closed. Free softphones can't reliably do this on iOS or modern Android.

  - **One-time $9.99 purchase** — no subscription, lifetime updates. Bria's mobile app is subscription-only at $4.95+/month.

  - **Multiple SIP accounts** — VoIP.ms alongside Twilio, a work PBX, or other providers in one app.

  - **End-to-end encryption** — ZRTP, SRTP, and TLS, all user-controlled.

## Troubleshooting

  - **Registration red / failing** — wrong sub-account username format. Use mainaccount_subaccount, not just the sub-account name.

  - **One-way audio** — ensure NAT=Yes in the VoIP.ms sub-account settings; on cellular this is almost always required.

  - **Calls connect but don't ring through to phone** — confirm the DID is routed to the sub-account in **Manage DID → Routing**.

  - **App doesn't ring when closed** — confirm push is enabled in Groundwire and at the OS level.

## Cost

ComponentCost

Groundwire (one-time)$9.99
VoIP.ms US DID~$0.85 / month
Outbound US calls$0.01 / min
Inbound US calls$0.009 / min
Typical light user~$2–3 / month

## Bottom line

VoIP.ms + Groundwire is one of the cheapest mobile phone setups available, with full SIP control, encryption, and reliable push.

**Also worth reading:** [is Groundwire worth paying for vs free softphones?](/blog/groundwire/is-groundwire-worth-paying-for-vs-free-softphones/) and [is Groundwire secure?](/resources/knowledge-base/is-groundwire-secure/)

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