Fixing Line Label Display in Polycom VVX devices on Version 5.7.x

Polycom have recently (few months ago) introduced the firmware upgrade version 5.7 for their VVX range devices. This firmware includes few of most wanted features for Skype for Business. Some of them are;

  • Common Area Phone support
  • SILK Codec support

Also, they have introduced a change to the DID number display on the device. This was an enhancement feature put in to VVX devices, when used with Skype for Business. In Polycom’s words;

“On VVX 300, 400, 500, and 600 series business media phones with the Skype for Business Base Profile, the Direct Inward Dialing (DID) number assigned to the user on the Skype for Business server displays on the on the Lock, Home, and Incoming Call screens. This feature is enabled by default on supported phones with the Skype Base Profile or shipped with Skype for Business enabled. The following figure shows the DID number on the Locked screen of a VVX 500 series business media phone.”

It looks like;


But, that’s on the Lock Scree. When it installed on a VVX 3xx device, it was looking like this on an unlocked device;file-5

When a standard user SIP URI is like sip:+618xxxxxxxx;ext=xxxxx where only 4 digit extension configure, it would have been fine.

But when the extension get lengthier than that, the DID number starting to get disappear to make room for additional digits in the extension. This looks really bad and confusing for the users who are using the device.

After escalating this further, Polycom have came up with a solution for this in their new firmware version 5.7.1. They have introduced a configurable option to change the number display, the way that the administrator wants.

The down side for this, is that a Provisioning server is required to fix this. If a provisioning Server already exist, then setting the below code in a configuration file will fix the display of the number to just to display the DID number. And not the full URI with the extension.

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<!-- Generated features.cfg Configuration File -->
<polycomConfig xmlns:xsi="" xsi:noNamespaceSchemaLocation="polycomConfig.xsd">
 <up up.DIDFormat="NumberOnly"></up>
 <reg reg.1.useTelUriAsLineLabel="false" />

Once this is configured and pushed in to devices, the number display will change to set as below;file-6

The display is way better with proper E.164 formatted DID number.

It’s a fairly straight forward fix for the environments that already have Provisioning server deployed. For others, not so much 🙂


Direct Routing with Microsoft Teams

You might have already heard about “Direct Routing” with Microsoft Teams and what it does. In case you haven’t;

Direct Routing is there for the people who wants to use their on PSTN Trunks and SBC with Microsoft Teams. You can call it BYOT (Bring Your Own Trunk). The SBC must be a Teams certified SBC for this to work. And you can use it with a SIP Trunk, or an ISDN link (or with FXO lines if you really want). The connectivity will be as shown below;


License Requirement

In order to use Direct Routing, Microsoft Calling Plan license is required. Preferably, Microsoft 365 E5 license with complete set of features. Otherwise, an E3 license with add-on Phone System licenses to enable PSTN calling capability. Below are the license options that can be used;

Required licenses:

  • Office 365 Enterprise E3 (including SfB Plan2, Exchange Plan2, and Teams) + Phone System
  • Office 365 Enterprise E5 (including SfB Plan2, Exchange Plan2, Teams, and Phone System)

Optional licenses:

  • Calling Plan
  • Audio Conferencing

SBC Requirement 

As i mentioned above, not all SBCs are capable of supporting Direct Routing. As for now, there’s only Ribbon Communications (former Sonus) and AudioCodes SBCs are in the certified list. Below are the official document from the vendors;

AudioCodes :

Ribbon Communications : 

Will it work with Analogue?

Yes!. It can be integrated with an on-premises Analogue Gateway. However, Teams infrastructure in Microsoft 365 will have nothing to do with the Analogue configuration. The on-premises SBC will need to handle the routing between Teams endpoints and Analogue Gateway.

Will it work with Microsoft Phone System (Skype for Business Online)?

Unfortunately, Direct Routing is not supported for Skype for Business Online. Only possible way to use an on-premises SBC with BYOT is, to use the CCE (Cloud Connector Edition). Both of above mentioned vendors are certified for CCE as well.

I’d strongly recommend not to use this path as the CCE is expensive and soon to be obsolete option. Using Teams with Direct Routing will be the most cost effective and future proof option to consider.

I’m hoping above high level explanation will be sufficient to understand the concept behind how Direct Routing works. I’m planning to write a deployment and configuration guide regarding this in near future, when this becomes GA. Until then, please post any questions or clarifications in comments.