voipms: IP restriction on the setup checklist, getCDR checked against voip.ms's examples

docs/admin-guide/maintenance.md

@@ -142,7 +142,7 @@ backup.
 3. Run `./scripts/install.sh`. It keeps the existing `.env`.
 4. Run `./scripts/restore.sh <backup>`.
 5. If the public IP changed: update it on **Settings → Network**, change your DNS record and any
-   IP-based settings at voip.ms (IP authentication, API whitelist), then
+   IP-based settings at voip.ms (IP restriction, IP authentication, API whitelist), then
    `docker compose restart asterisk`.
 6. Desk phones fetch their setup from the host name, so they follow the DNS change.
 

docs/admin-guide/network.md

@@ -345,6 +345,9 @@ Someone with a stolen SIP password calling expensive international numbers is th
 real money. Keep:
 
 - international calling **off** at voip.ms and in **Outbound rules** unless you need it;
+- **IP restriction** on the voip.ms sub-account, allowing only your server's public IP: a stolen
+  trunk password used from another server skips every limit below
+  ([voip.ms setup](voipms.md#1-in-the-voipms-portal));
 - the voip.ms **balance alerts and spending limits** on;
 - the **desk phone network limit** above on if your phones are all in the office;
 - the **outside calls at once** limits (Settings → Security) as low as your office needs: per

docs/admin-guide/voipms.md

@@ -18,6 +18,11 @@ then; if a menu name below doesn't match, look for the closest one.
    - **International calling:** leave it **off** unless you need it. It's your best protection
      against toll fraud if a password ever leaks.
    - **Encrypted SIP traffic (TLS/SRTP):** optional; see [SIP over TLS](#sip-over-tls).
+   - **IP restriction** (edit the sub-account → Security): turn it **on** and allow only your
+     server's public IP. voip.ms then refuses outgoing calls from anywhere else, so a stolen
+     sub-account password can't be used from the thief's own server, where none of SelfPhoneNG's
+     limits apply. It needs a fixed public IP: if yours changes, outgoing calls fail until you
+     update it here (SelfPhoneNG emails admins when it sees the change).
 2. **Pick a POP server** near the PBX, e.g. `chicago1.voip.ms`. Write it down: the trunk and every
    number must use the same one.
 3. **Point each number at the sub-account** (DID Numbers → Manage DIDs → edit the number):