The SBC Edge and SBC SWe Lite support the following media modes:
RTP Media Manipulation Mode. A media session that requires media manipulation; these flows may be common with endpoints that communicate across enterprise and public boundaries. Configuration option includes:
RTP Proxy Media Mode. A media session that flows through the SBC but does not require media manipulation. Configuration options include:
RTP Direct Media Mode. A media session that does not flow through the SBC; these flows are common with endpoints that reside within the same physical premises. Configuration option includes:
Media Modes Supported
Media Mode and Capability | SBC Edge | SBC SWe Lite | Codec Negotiation | SRTP Negotiation | Network Support (NAT, etc.) |
---|---|---|---|---|---|
DSP | Yes | Yes | Yes | ||
Proxy Relay | No | No | Yes | ||
Proxy with Local SRTP | No | Yes | Yes | ||
Direct | No | No | No |
The
Specific configuration allows multiple media streams to be bundled in the Proxy Relay Media Mode or Direct Media Mode (through Audio/Fax Stream Mode and Video/Application Stream Mode). As a result, all media streams (Audio/Video/Application) are supported by the
Proxy with local SRTP mode introduced in the 7.0 release supports audio stream only, and does not support video.
While the audio media codec parameters are configurable in the
Various modes and call outcomes due to end-to-end compatibility are listed below:
Media Modes and Call Outcomes
Inbound/Outbound peer Media compatibility | SBC Audio/Video Mode Configuration | Call Outcome | Comments |
---|---|---|---|
Audio-codec Compatible & SRTP Incompatible | Proxy with local SRTP/Disabled | Audio | SRTP is negotiated per leg basis, and end-to-end audio call succeeds. |
Video-Disabled | |||
Audio-codec incompatible irrespective of SRTP compatibility | Proxy with local SRTP/Disabled | Call Failure | End-to-end codec compatibility does not exist. |
Video-Disabled | |||
Audio-Compatible | Proxy Relay/Proxy Rely or Direct/Direct | Audio/video call | End-to-end compatibility exists for audio and video. |
Video-Compatible | |||
Audio-Compatible | DSP/Proxy Relay | Audio/video call | End-to-end compatibility exists for audio and video, and Audio media uses a DSP in the Unable to show "metadata-from": No such page "_space_variables" . |
Video-Compatible | |||
Audio-Compatible | Proxy Relay/Proxy Relay or Direct/Direct | Audio call | End-to-end compatibility does not exist for video. |
Video-Incompatible | |||
Audio-Compatible | DSP/Proxy Relay | Audio call | End-to-end compatibility does not exist for video, and Audio media uses a DSP in the Unable to show "metadata-from": No such page "_space_variables" . |
Video-Incompatible | |||
Audio-Incompatible | Proxy Relay/Proxy Relay or Direct/Direct | Video only call | End-to-end compatibility does not exist for audio, and video only call works provided end-to-end compatibility. |
Video-Compatible | |||
Audio-Incompatible | DSP/Proxy Relay | Audio/video call | End-to-end compatibility does not exist for audio and audio media requiring a DSP in the Unable to show "metadata-from": No such page "_space_variables" . |
Video-Compatible | |||
Audio-Incompatible | Proxy Relay/Proxy Relay or Direct/Direct | Call fails | End-to-end compatibility does not exist for audio and video. |
Video-Incompatible | |||
Audio-Incompatible | DSP Proxy Relay | Audio Call | End-to-end compatibility does not exist for audio and video and audio media requiring a DSP in the Unable to show "metadata-from": No such page "_space_variables" . |
Video Incompatible | |||
Audio-Incompatible | Proxy Relay/proxy Relay or Direct/Direct | Call fails | End-to-end compatibility does not exist for audio and video. |
Video-Incompatible |
For Direct Media calls, the SIP peer devices should be reachable by each other without the SBC being in the middle. The media would not go through the SBC, and the immediate peer devices are allowed to send/receive media to each other.
The following steps outline the basic configuration for using a Video Call. See Usage Examples below for specific configuration information. For detailed field configuration, see Creating and Modifying SIP Signaling Groups and Creating and Modifying Entries to Call Routing Tables.
Through the SIP Signaling group's Media Information, a mode could be selected for each media stream type. See Creating and Modifying SIP Signaling Groups.
Through the Call Route Table, a media priority can be selected for each of these media stream types (Audio/Fax Stream, Video/Application Stream). See Creating and Modifying Entries to Call Routing Tables.
Calls in RTP Proxy Mode that do not require DSP: any codec not suppored by DSP (i.e., Opus) is able to establish an audio path in RTP Proxy mode.
Component | How to Configure |
---|---|
Inbound Signaling Group Entry |
|
Outbound Signaling Group Entry |
|
Call Route Entry |
|
Proxy Mode enables multiple media streams to be bundled in Proxy Relay Media Mode; all media streams (audio/video/application) are passed through the
For this configuration there are two outcomes:
Component | How to Configure |
---|---|
Inbound Signaling Group Entry |
|
Outbound Signaling Group Entry |
|
Call Route Entry |
|
Direct Mode enables multiple media streams to be bundled in Direct Media Mode; all media streams (audio/video/application) are bypassed by the SBC.
For Direct Media Calls, the SIP peer devices should be reachable by each other without the SBC being in the middle. The media would not go through the SBC and the immediate peer devices are allowed to send/receive media to each other.
For this configuration, there are two outcomes:
Component | How to Configure |
---|---|
Inbound Signaling Group Entry |
|
Outbound Signaling Group Entry |
|
Call Route Entry |
|
Mixed Media (Hybrid) mode allows the
For this configuration, there are two outcomes:
Component | How to Configure |
---|---|
Inbound Signaling Group Entry |
|
Outbound Signaling Group Entry |
|
Call Route Entry |
|
Recommendations when using the video mode to avoid seeing video call failures:
Call un-hold, might have a period of no video depending upon the the video-fast-update in its SIP-INFO and/or RTCP. After observing different phone end points, this could range from 0 (GrandStream) to 30 seconds(Bria).
Early 183 does not function since the
Ring-back generation is not available for all-proxy call.
Dead call detection does not work for all-proxy calls since the
What is hybrid mode?
Audio media is processed through the DSPs and Video media is passed through the Network Processor level without involving the DSPs.
When will you use hybrid mode?
This configuration is best suitable for the call routes that need to have audio transcoded, and where the same route needs to handle video calls as well.
How does it compare with Proxy mode?
In Proxy Mode, both the audio and video media are passed through the Network Processor level without involving the DSPs.
What comes extra compared with 3.0 release?
For audio calls, the call handling with respect to Offer/Answer remains identical.
What comes extra compared with 3.1 release?
For audio calls, the call handling with respect to Offer/Answer remains identical.
What is taken away enabling this? (transfer issues, etc.)
There is no difference in audio call processing. However, if the call is video, then transferring the call is supported only in Broadsoft like deployments, wherein it requires configuring the