The behavior difference between the E3 and E5 accounts is almost certainly due to licensing and/or voice configuration on the E5-based room account, not the fact that it is E5 itself.
From the provided information:
- Teams calling to external devices (such as Cisco endpoints via PSTN or a SIP trunk/Direct Routing/CVI) requires:
- A Teams Phone–enabled user (Phone System entitlement) and
- A working PSTN or SIP/CVI connectivity configuration for that user.
- If some users can make calls and others cannot, the common cause is missing or incorrect voice licensing and policies on the affected account, even when the base Microsoft 365 license (E3 vs E5) looks correct.
For the E5 meeting-room account that cannot call the Cisco device, verify the following against a working E3 user:
- Check that the account has the correct Teams Phone licensing
- Ensure the room account has the Teams Phone entitlement (for example, Phone System or “Teams Phone with Calling Plan” or equivalent) assigned, not just the base E5 license.
- If using Microsoft Calling Plans, confirm a Calling Plan license is assigned to that room account.
- If using Direct Routing or Operator Connect, confirm the room account is configured like other working users.
- Validate Enterprise Voice and voice settings
- In Teams PowerShell, compare the E5 room account with the working E3 user using
Get-CsOnlineUser and check at least:
-
EnterpriseVoiceEnabled
-
HostedVoiceMail
-
OnPremLineURI
- These must be set correctly for the room account, as described in the Direct Routing enablement guidance. If
EnterpriseVoiceEnabled is False or OnPremLineURI is missing/incorrect, outbound calls can fail.
- Confirm Online Voice Routing Policy (if using Direct Routing)
- If Direct Routing is used, ensure the room account has an Online Voice Routing Policy (OVRP) that:
- Contains a pattern that matches the Cisco device’s number.
- Uses a usage profile and gateway that are enabled and valid.
- If the OVRP has invalid or hidden characters (for example, copied from Word), remove and recreate it in a plain-text editor.
- Compare PSTN connectivity path
- If the E3 user reaches the Cisco device via PSTN or a SIP trunk, ensure the E5 room account is routed through the same path (same SBC, same routing policy, same dial plan behavior).
- Test with another E5 user
- If another E5-licensed user (non-room) can call the Cisco device successfully, the issue is specific to the room account’s voice configuration, not to E5 licensing in general.
In summary, the E5 room account likely lacks proper Teams Phone/Enterprise Voice enablement or a correct voice routing policy, whereas the E3 user is fully configured. Align the room account’s Teams Phone licensing and voice configuration with the working E3 user to resolve the calling issue.
References: