In this section:
In a Distributed SBC configuration, each component scales independently in its own cluster depending upon call needs and the overall implemented traffic model. The S-SBC cluster instances discover the server instances using standard DNS resolution of policing and DSP services that are provided by the respective M-SBC and T-SBC cluster.
% set system dsbc cluster type <dsp, mrf, policer>
The SBC supports the following cluster profiles to resolve inter-cluster FQDN port communication for the M-SBC and T-SBC nodes involving instances communicating with other clusters:
The D-SBC uses the Signaling IP address of the T-SBC hosting the DSP to provide services that include Transcoding/tone detection, Secured transport connection (crypto) like SRTP (Media), RTCP generation, FMTD detection, Legal Interception, Recording and Transcoding, Trans-rating or Tran-sizing flows.
% set system dsbc cluster type dsp dnsGroup <DNS group name> fqdn <FQDN: 1-63> state <disabled | enabled>
SBC SWe systems in an OpenStack cloud environment inter-operate with a third-party transcoding platform called Media Resource Function (MRF) to transcode audio and relay video/T140. Only distributed SBC (D-SBC) SWe systems on OpenStack supports this feature.
Prior to release 7.1.0, the SBC invoked MRF only for audio streams to achieve transcoding. Non-audio streams were relayed end-to-end even when the audio was sent to the MRF. Teletype (TTY) as the legacy service offered through encoding text characters as tones that are embedded in a carrier (PCMU, PCMA, or EVRC) media stream. The T.140 streams carry text as a separate payload. Henceforth, the SBC invokes MRF for T.140 and TTY interworking to achieve transcoding. When T.140 and TTY interwork, text characters exchange between the T.140 stream and the tones carried inband with the audio. If the audio is pass-through and T.140 requires transcoding, the SBC does not invoke MRF and instead rejects the text stream on the offer leg (see the following call flow). Keep in mind that T.140 pass-through scenarios are supported without any MRF interaction. This feature does not support sessions that only have a T.140 stream. The SBC does not invoke T.140 and TTY interworking when T.140 is present on both legs and has different transmission rates, or a difference in redundancy packet support. Only the SBC SWe on OpenStack (D-SBC) supports this feature.
For additional feature functionality details, refer to Invoking MRF as a Transcoder for D-SBC.
The CLI syntax, parameter descriptions and command examples for configuring a MRF profile on a S-SBC is provided below.
Use the global callRemoteMediaStatus and callResourceDetailStatus commands to see when MRF is used for transcoding a call (resType
= "dresMrf").
% set system dsbc cluster type mrf mrfFqdn <domanin name> mrfIpAddress <IP address> mrfPort <0-65535> mrfRequestUri <Request URI> mrfRoutingType <IpAddress | fqdn> mrfTgName <trunking group name> mrfTransportType <TCP| TLS| UDP> state <disabled | enabled>
The MRF server is configured as either FQDN or IP address based on the mrfRoutingType
setting.
The D-SBC uses the policer cluster of type M-SBC to provide policing services that include DoS/DDoS Protection, Topology Hiding (IPv4, IPv6, IPv4/IPv6 inter-working), Media Rate Limiting, VLAN Tagging, Far End NA(P)T Learning, RTP Inactivity Detection, SRTP Relay, ACLs and Micro Flows. This cluster configuration is applicable only to the S-Node, and helps it identify the seed node of the M-Cluster with a FQDN. The DNS Group configuration tells which DNS Group to use to resolve the specified FQDN.
% set system dsbc cluster type policer dnsGroup <DNS group name> fqdn <FQDN: 1-63> state <disabled | enabled>
To configure a DSP cluster profile:
set system dsbc cluster type dsp dnsGroup SWeDNS fqdn tsbc.tcluster.com state enabled commit
To configure an MRF as IP address:
set system dsbc cluster type mrf mrfRoutingType IpAddress mrfPort 5060 mrfIpAddress 10.54.1.1 mrfTgName SBX_55461_IMS_TG mrfRequestUri MRF-SERVER mrfTransportType UDP state enabled commit
To configure an MRF as fqdn:
set system dsbc cluster type mrf mrfRoutingType fqdn mrfPort 5060 mrffqdn sonusnet.com mrfTgName SBX_55461_IMS_TG mrfRequestUri MRF-SERVER mrfTransportType UDP state enabled commit