In this section:
Not supported by SBC SWe Lite in this release.
ICE-Lite Overview
The ICE-Lite (Interactive Connection Establishment) feature interfaces to the Microsoft TEAMS Direct Routing interface. The SBC integrates Microsoft Teams clients by acting as an ICE Lite agent endpoint for SIP calls involving Network Address Translators (NATs). This feature enables direct routing between an existing enterprise voice infrastructure (that is, the PSTN carrier and SIP trunks used for trunking services) and the Microsoft Phone System in Office 365. The SBC acts as a PSTN gateway; sessions for Microsoft Teams users can be routed directly to the PSTN through the SBC.
How does the SBC interoperate with Microsoft TEAMS?
As communications sessions are set up and negotiated, Session Description Protocol (SDP) is used to carry the IP addresses and ports of all participants that receive RTP streams. Because Network Address Translators (NATs) alter IP addresses and ports, the exchange of local IP addresses and ports may not be sufficient for establishing connectivity. Acting as an ICE-Lite agent, the Unable to show "metadata-from": No such page "_space_variables" responds to connectivity checks as required to establish and verify connectivity.
A Teams client initiates the media flow and becomes the controlling ICE agent for the SBC. During the establishment of a media session that uses ICE-Lite, the Unable to show "metadata-from": No such page "_space_variables" goes through candidate gathering and connectivity check phases that occur before the controlling agent (optionally) sends a final SDP offer that includes the best local and remote candidates selected for a media flow. The Unable to show "metadata-from": No such page "_space_variables", acting as ICE-Lite agent, acknowledges the final offer with an answer, and both endpoints use the selected candidate pair for the media flow.
Configuration
Configuration for ICE-Lite is completed through the SIP Signaling Group.
For detailed configuration for using ICE-Lite with Microsoft TEAMS, refer to Best Practice - Configuring SBC Edge for Select Microsoft Teams Direct Routing Related Migration Scenarios.
For details on ICE-Lite configuration, refer to Creating and Modifying SIP Signaling Groups.
The screen shot below is for an SBC 2000.
SIP Signaling Group - ICE-Lite Configuration
The following fields must be configured to enable the ICE-Lite feature:
ICE Support
ICE Support - Field Definition
| Field | Location | Definition |
|---|---|---|
| ICE Support | Settings > SIP Signaling Group | Enables/disables ICE Lite support. This field must be enabled for ICE-Lite to be active. |
ICE Mode
ICE Mode - Field Definition
| Field | Location | Recommended Configuration |
|---|---|---|
| ICE Mode | Settings > SIP Signaling Group | Specifies the Interactive Connection Establishment (ICE) mode. Valid entries: For SBC 1000/2000: Lite or Full. To access the ICE-Lite feature, configure this field as Lite. For SBC SWe Lite: This field is configured as Lite automatically when ICE support is Enabled. |
Interoperability Notes
ICE-Lite impacts the following on the SBC 1000/2000 and SBC SWe Lite.
| SBC Feature | Supports | Does not Support |
|---|---|---|
| ICE Restarts |  | |
TURN server operation With some topologies, when the ICE protocol requires use of a TURN server to | | |
STUN Server Operation in Full Mode SBC 1000/2000 supports ICE full mode using STUN server to gather candidates. STUN server is required to support ICE full mode. | | |
ICE-Lite Mode When acting as an ICE Lite agent the SBC is connected to a public internet using only single host UDP candidate. | | |
RTP and RTCP RTP and RTCP as separate components for each candidate. | | |
IPv4 only ICE protocol does not guarantee consecutive ports for RTP and Real-Time Transport Control Protocol (RTCP). | | |
Media Send/receive media to RTP and RTCP on nonconsecutive ports on the SBC. | |
Overview
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