BFCP Support
Binary Floor Control Protocol (BFCP), defined in RFC 4582, is a protocol for controlling the access to the media resources in a conference.
Cisco Unified Border Element (SP Edition) was earlier known as Integrated Session Border Controller. It is referred to in this document as the session border controller (SBC).
For a complete description of the commands used in this chapter, refer to the Cisco Unified Border Element (SP Edition) Command Reference: Unified Model at:
http://www.cisco.com/en/US/docs/ios/sbc/command/reference/sbcu_book.html
For information about all the Cisco IOS commands, use the Command Lookup Tool at http://tools.cisco.com/Support/CLILookup or a Cisco IOS master commands list.
Feature History for BFCP Support
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This feature was introduced on the Cisco ASR 1000 Series Routers. |
Contents
Prerequisite for BFCP Support
Following is the prerequisite pertaining to the BFCP Support feature:
Restrictions for BFCP Support
Following are the restrictions pertaining to the BFCP Support feature:
- The SBC treats a generic media stream the same way it treats other media streams. Therefore, a call is released only if all the media streams are reported as being inactive. The Media Packet Forwarder (MPF) media timer is processed in the same way as the other voice or video streams pertaining to the BFCP stream.
- A BFCP media stream and a generic media stream do not have a bandwidth specified. Therefore, it can be policed only by the MPF, and not the Call Admission Control (CAC) total bandwidth limits.
- The SBC does not support the generic TCP streams or BFCP over TCP. Therefore, a request to add a TCP stream to the generic media stream configuration gets rejected.
- H.323 calls or H.323-SIP interworking calls are not supported.
Information About BFCP Support
The BFCP Support feature supports BFCP over UDP in the SBC by configuring BFCP as a recognized generic media stream that can be forwarded using the best-effort traffic class.
Generic media streams are media streams in which the media (m)-line definition uses * instead of a codec list, for example, m=application port UDP/BFCP *. By default, the SBC cuts these m-lines out of the SDP offers and replies by setting the port to zero. These media lines carry no bandwidth information and therefore, cannot be policed against CAC limits, denial of service, or media theft attacks of the SBC.
The BFCP Support feature introduces the best-effort traffic class that allows policing of these media lines in the media forwarder.
The SBC can be configured to accept specific generic media streams. After this, the accepted generic media streams are added to the best-effort traffic class. MPF implementation supports the best-effort traffic class by policing the actual usage of the aggregate of these streams.
Best-Effort Traffic Class
Prior to Cisco IOS XE Release 3.3S, the media streams had their bandwidth specified for audio and video streams, or were not subjected to any policing, such as T120. From Cisco IOS XE Release 3.3S, the SBC is configured to accept arbitrary type and number of generic media streams. Some of the BFCP streams can now have low bandwidth protocol messages. The best-effort traffic class simplifies packet policing because it allows a media forwarder to handle such streams cumulatively. The best-effort traffic class rate limit is 1Mbps cumulatively.
Deploying BFCP Support
Figure 32-1 shows a scenario where the SBC can be deployed for the BFCP Support feature. In this scenario, the SBC is located in the Service Provider network, allows inter enterprise calls between different VPNs, and protects the core network.
Figure 32-1 BFCP Deployment Scenario
Configuring BFCP Support
This section describes how to configure the BFCP Support feature on the SBC.
SUMMARY STEPS
4. stream-list stream-list-name
6. generic-stream media-type { application | message } transport udp protocol protocol-name
8. cac-policy-set policy-set-id
10. table-type {policy-set | limit { list of limit tables}}
12. action [next-table goto-table-name | cac-complete]
13. generic-stream caller generic-stream-list
14. generic-stream callee generic-stream-list
20. show sbc service-name sbe stream-list
21. show sbc service-name sbe cac-policy-set id table name entry entry
DETAILED STEPS
The following example shows the output of the show sbc sbe stream-list command:
Configuration Example of BFCP Support
Following is a configuration example of the BFCP Support feature on the SBC: