On a compatible Spectralink SIP device, create one line with sip.39networks.net on port 5061 over TLS, enter the customer-specific identity and password, apply SRTP and confirm a stable registration before testing calls.
Settings used in this guide
These are public service values, not your password or account-specific authentication ID.
| SIP registrar / proxy | sip.39networks.net |
|---|---|
| SIP signalling port | 5061 |
| SIP transport | TLS |
| Media security | SRTP |
| Registration interval | 300 seconds |
| Separate outbound proxy | Use the registrar unless your activation email names a separate outbound proxy |
| DTMF method | Confirm in your UKDDI activation email |
| Approved codec order | Confirm in your UKDDI activation email |
| Outbound caller ID policy | Use only a UKDDI number allocated and approved for your account; confirm the required format in your activation email |
Confirm the Spectralink model and account are compatible
Wi-Fi and DECT handsets depend on correctly designed radio infrastructure as well as SIP. A DECT server or base may own the registration, and model families use different management platforms. Confirm interoperability and firmware first.
Use this guide only when UKDDI has issued a direct handset account. If the Spectralink phone is an extension of 3CX, Asterisk, FreeSWITCH or another PBX, register it to that PBX instead and configure UKDDI once at the trunk.
- Update to a supported stable firmware after reading the model release notes and taking a configuration backup.
- Confirm the phone supports TLS, current certificate validation and the issued SRTP method.
- Connect the phone to a trusted voice network with working DNS, NTP and outbound access to the issued service.
- Factory reset only when authorised and only after preserving any required provisioning and recovery details.
Open the Spectralink SIP account settings
Use the supported Spectralink administration interface or provisioning system to open the line registration or call-server profile. Enter SIP identities and server details, then apply transport, certificate, media and codec policy.
- 1Find the phone address safely
Read the local IP from the device status screen or authorised network inventory. Do not expose its web interface through a public port-forward.
- 2Sign in as administrator
Use a unique administration password, replace any default credential and restrict management to the trusted network.
- 3Choose one free line
Use a line/account not controlled by another provider profile and give it a recognisable UKDDI label.
Enter the UKDDI registration values
Map Address/User to the issued SIP user, Auth User to the authentication ID, Password to the secret and Registrar/Server to sip.39networks.net on 5061 via TLS.
- 1Set the registrar
Use sip.39networks.net on 5061 and select TLS. Use the hostname so TLS certificate validation and DNS continue to work.
- 2Enter all three identity fields
Map the SIP user/account, authentication ID and password separately exactly as shown in the activation email. The telephone number is not necessarily any of these values.
- 3Set the outbound proxy
Use the registrar unless your activation email names a separate outbound proxy. Leave an optional field empty when the product accepts the registrar directly and no separate proxy was issued.
- 4Set the refresh
Request 300 seconds or let the phone accept the shorter value returned by the registrar.
- 5Save and inspect status
Apply the account and confirm Registered or a 200 OK response. Do not assume that a green network icon means the SIP line registered.
Do not photograph, email or publish a page containing the SIP password. Redact it from configuration exports and packet captures.
Apply security, codec and feature settings
Provision managed mobile handsets centrally. Validate Wi-Fi roaming, QoS and certificate deployment separately from SIP registration, and never email a credential-bearing support bundle unredacted.
| Phone setting | UKDDI value or rule |
|---|---|
| SIP transport | TLS |
| SIP port | 5061 |
| Certificate verification | Keep enabled; use sip.39networks.net and a current clock/trust store |
| Media encryption | SRTP using the method in the activation email |
| DTMF method | Confirm in your UKDDI activation email |
| Codec priority | Confirm in your UKDDI activation email |
| Registration interval | 300 seconds |
| Caller ID | Use only a UKDDI number allocated and approved for your account; confirm the required format in your activation email |
Test the Spectralink phone end to end
- 1Watch one registration refresh
Leave the status visible for longer than 300 seconds and confirm it does not alternate between registered and failed.
- 2Receive an external call
Call the allocated number from another network and verify the intended line rings, answers and shows sensible caller identity.
- 3Place a permitted outbound call
Call a number you control and confirm the approved UKDDI caller ID. Do not test premium or emergency destinations as an ordinary setup check.
- 4Check the complete media path
Verify speech in both directions, keypad tones through an IVR, hold, transfer and a call lasting more than five minutes.
- 5Record a clean fault report
Provide the model, firmware, MAC address only if requested, test time/timezone, direction, numbers and SIP response. Remove passwords and Authorization data.
Troubleshoot without weakening the network
| Symptom | Check first |
|---|---|
| Not registered | DNS/NTP, sip.39networks.net:5061, TLS, identity mapping and the exact SIP response |
| TLS error | Hostname, device clock, CA trust and current firmware |
| Registers then drops | Provisioning overwrite, NAT state, 300 seconds and duplicate use of the same account |
| One-way audio | Voice VLAN routing, NAT, local RTP policy and whether a SIP ALG is rewriting SDP |
| Keypad tones fail | Confirm in your UKDDI activation email and the negotiated codec/media policy |
A registered phone normally creates its own outbound state. Do not forward SIP from the whole internet to a desk phone or place it in a DMZ as a troubleshooting shortcut.