One SIP account can log in on multiple devices
(Also called multi-registration or parallel registration)
This means the same SIP username/password can be used simultaneously on:
- Desk phone
- Softphone (PC)
- Mobile SIP app
- Another SIP phone
All devices become active at the same time.
📌 Behavior:
| Feature | What Happens |
|---|---|
| Incoming Call | All registered devices ring at the same time. First to answer wins. |
| Outgoing Caller ID | Same Caller ID regardless of device. |
| Presence / Message Sync | Depends on PBX and SIP device—sometimes supported, sometimes not. |
| Line Status | Not all phones show "busy" correctly when another device is in use (depends on PBX). |
📌 Used for:
- Hot desking
- Using one extension on mobile + desktop
- Remote work scenarios
Systems like 3CX, Yeastar, Asterisk (with PJSIP), FreePBX, Astersik support this if configured.
❌ One SIP account can log in to ONLY one device at a time
(Sometimes called single registration enforcement)
If you try to register the same account on another device:
- The new device kicks out the old one, or
- Registration fails with 403 or 486 Busy Here, depending on system.
📌 Behavior:
| Feature | Result |
|---|---|
| Multiple device login | ❌ Not allowed |
| Security | Higher — prevents sharing credentials |
| Device tracking | PBX always knows which device is using that extension |
📌 Used for:
- Large corporate environments
- Call centers
- Security-focused deployments
- Preventing account sharing or fraud
Which is better?
| Feature | Multi-Device Login | Single Device Login |
|---|---|---|
| Mobility | ⭐⭐⭐⭐⭐ | ⭐ |
| Security | ⭐⭐ | ⭐⭐⭐⭐⭐ |
| IT control | ⭐⭐ | ⭐⭐⭐⭐⭐ |
| Redundancy (phone + softphone) | ⭐⭐⭐⭐ | ⭐ |
| Call handling consistency | ⭐⭐ | ⭐⭐⭐⭐⭐ |
At Azentix, we can assist you to increase the mobility and redundancy feature even with one Single Device Login. Please contact us for further details.