Configure the SBC for Microsoft Teams Direct Routing

1. Select VoIP from the Configuration Menu on the left-hand side. 

2. Configure the system’s VoIP settings.
   
   
   

    

   Configuring VoIP Parameters

   Parameter	Example Configuration Value
   Enable LLDP	Enabled (default)
   LLDP Broadcast Interval (sec)	30 (default)
   TFTP Server IP Address	Disabled
   Use ALG Alias IP Addresses	Disabled
   Public NAT WAN IP Address	Public WAN IPv4 address when using a 1-to-1 NAT configuration
   Private NAT LAN IP Address	Private LAN IPv4 address when using a 1-to-1 NAT configuration
   Do Strict RTP Source Check	Disabled
   Enable Client List Lockdown	Disabled
   Allow Shared Usernames	Disabled
   Strip G.729 from Calls	Disabled
   Route all SIP Signalling Through B2BUA	Enabled
   Enable Microsoft Feature	Enabled
   Enable Comfort Noise Generation (CNG)	Enabled
   Enable User-Agent Header Pass-Through	Disabled
   Enable SRTP Support	Enabled
   Enable MKI Support	Disabled Note: This is optional. This depends on whether or not MKI support is enabled on MS Teams.
   H.225/H.245 Port Range	14085-15084 (default)
   RTP Port Range	16386-18385 (default)
   RTP Packetization Time (ms)	20
   Prioritize Microsoft Teams	Not Required for MS Team. The system will automatically prioritize signaling and media. This setting is used when the system is “NATing” MS Teams traffic.
   Calculate RTT	Enabled (default)

    

3. Configure the SIP Server Settings for the SIP trunking service parameters.
   
   
   

    

   Configuring SIP Server Settings Parameters

   Parameter		Example Configuration Value
   SIP Server Address		siptrunk.example.com
   SIP Server Port		5060 (Verify with your SIP trunking provider which SIP port to configure.) Note: If the FQDN resolves to a different port for the SIP Server Address the system will use the port returned in the DNS query response.
   SIP Server Transport		UDP
   Enable SRTP		Disabled
   Use Custom Domain		Disabled
   SIP Server Domain		Not set
   List of SIP Servers		None
   Enable Multi-homed Outbound Proxy Mode		Disabled
   Enable Transparent Proxy Mode		Disabled
   Limit Outbound to Listed SIP Servers		Disabled
   Limit Inbound to Listed SIP Servers		Disabled
   Include UPDATE in Allow		Enabled
   PRACK Support		Enabled
   GEOLOCATION Support		Enabled
   Call Audit Support		Disabled
   Stale Client Time (m)		1440 (default)
   Session Timer Support		Enabled
   Session Refresh Interval (s)		1800 (default)
   UDP	Client Listening Port(s)	5060,5070,5075 (default)
   UDP	Server Facing Port	5060 (default)
   UDP	REGISTER Restricted to Port	0 (default)
   TCP	Port	5060 (default)
   TCP	Timeout (minutes)	10 (default)
   TLS	Port	5061
   TLS	TLS Protocol	TLSv1.2
   TLS	Ciphers String	TLSv1.2+HIGH:!eNULL:!aNULL
   TLS	LAN	Certificate: Default	Policy: No Check
   TLS	WAN	Certificate: SBC_Cert	Policy: No Check
   TLS	Exclude sips headers for TLS Transport	Enabled
   NAT Traversal		Disabled (default)
   SDP Codec Operation		Allow only given codecs
   SDP Section that will be modified		Audio
   Codecs (comma separated list)		PCMU, PCMA, CN, telephone-event
   Reject when No Match Codec		Enabled
   Strip Matched Expressions		\ba=candidate:.*\b a=rtcp-mux \ba=ice-.*\b
   SIP Use New Port On Hold Resume		Disabled
   Priority Number 1: Priority Number 2: Priority Number 3: Priority Number 4:		Not set
   Enable SIP Statistics		Enabled

    

4. Click Submit to apply changes.

Configuring the B2BUA and Header Manipulation rules

This step discusses how to configure a B2BUA trunking device to the WAN side of the system for MS Teams support. Header manipulation rules are used to modify the headers required for interoperability to-and-from MS Teams and to-and-from the SIP trunking provider.

1. Choose VoIP > SIP > B2BUA from the Configuration Menu on the left-hand side.

2. Add a B2BUA Trunking Device for the MS Teams cloud servers and click Update. Then, scroll to the bottom and click Submit.
   
   

   Configuring the First B2BUA Trunk

   Parameter	Example Configuration Value
   Name	Teams1 Arbitrary name (alphanumeric characters only)
   Model	Microsoft Teams
   Address (IP/FQDN)	sip.pstnhub.microsoft.com
   Use DNS SRV	Not set for MS Teams
   Port	5061
   Transport	TLS
   SRTP	Mandatory
   Source FQDN	sbc1.rbbn.com Note: This name must be identical to the name configured as the PSTN gateway.
   Username	Not used for MS Teams
   Password	Not used for MS Teams

   
   

   Configuring the Second B2BUA Trunk

   Parameter	Example Configuration Value
   Name	Teams2 Arbitrary name (alphanumeric characters only)
   Model	Microsoft Teams
   Address (IP/FQDN)	sip2.pstnhub.microsoft.com
   Use DNS SRV	Not set for MS Teams
   Port	5061
   Transport	TLS
   SRTP	Mandatory
   Source FQDN	sbc1.rbbn.com (This name must be identical to the name configured as the PSTN gateway)
   Username	Not used for MS Teams
   Password	Not used for MS Teams

   
   

   Configuring the Third B2BUA Trunk

   Parameter	Example Configuration Value
   Name	Teams3 Arbitrary name (alphanumeric characters only)
   Model	Microsoft Teams
   Address (IP/FQDN)	sip3.pstnhub.microsoft.com
   Use DNS SRV	Not set for MS Teams
   Port	5061
   Transport	TLS
   SRTP	Mandatory
   Source FQDN	sbc1.rbbn.com (This name must be identical to the name configured as the PSTN gateway)
   Username	Not used for MS Teams
   Password	Not used for MS Teams

3. Create a routing group for the MS Teams servers with the Trunking Group Availability function.
   
   

   
   

   Configuring the Routing Group

   Parameter		Example Configuration Value
   Group Name	TeamsGroup	NA
   State		Display Only
   Keep Alive		Enabled
   Load Balance		Optional
   Invite Failover		Enabled
   Trust Enabled		Enabled
   Trusted List		sip-all.pstnhub.microsoft.com
   Members for Group		TeamsGroup
   Keep Alive Interval		60 (default)
   Error Response		Not Set
   From User		Not Set
   To User		Not Set
   Backoff on No Response		Enabled
   Regular with max. Interval	Enabled	0 sec (default)
   Random with max. Interval	NA	NA
   Failover upon Invite Responses		503
   Fallback with auto keep alive		Not Selected
   Fallback Interval	Enabled	60 (s) (default)

4. Choose VoIP > SIP > B2BUA from the Configuration Menu on the left-hand side. Header manipulation rules are used to modify the headers required for interoperability to-and-from MS Teams and to-and-from the SIP trunking provider.
5. Scroll down to Actions and add the actions mentioned in the following steps, and associated HMR rules.
6. The first Actions is “ToTeams”. This rule has an associated “Match” rule for calls going to Teams.
   
   1. Configure the parameters in the actions pane.
   2. Configure each Header Value one at a time and click Add before creating the next rule.

   3. Click Update and then click Submit to save the action.
      
      

      Note

      In the example given in the following table, the dialing code +1 is used in reference to the USA. Change it to the dialing code of the country of your choice. 

      Configuring the ToTeams Action

      Parameter		Example Configuration Value
      Name		ToTeams Arbitrary name (alphanumeric characters only)
      Send To	Trunking Device	TeamsGroup
      Prioritize		Not used for MS Teams
      Refer to Re-INVITE		Enabled
      Serial Hunting		Not used for MS Team
      E.164 Conversion rule		None
      Conversion mode		Add (default)
      Request-URI		'sip:+1' + $to.uri.user + '@' + $env.target_domain + ':' + $env.target_port + ';user=phone'
      From		'<sip:+1' + $from.uri.user + '@' + $env.target_src_domain + ':' + $env.target_port + ' ;user=phone>'
      To		$to.dispname + '<sip:+1' + $to.uri.user + '@' + $env.target_domain + ':' + $env.target_port + ';user=phone>'
      Contact		'<sip:+1' + $from.uri.user + '@' + $env.target_src_domain + ':' + $env.out_intf_port + ';transport=TLS>' + $contact.parameter

7. The second action is FromTeams2ServerAnonymous. This rule has an associated “Match” rule for calls with “Anonymous” in the SIP URI. For example, when a Teams caller is blocking their number, the SIP From URI will have the following format:
   From: "Anonymous"sip:anonymous@anonymous.invalid:5060.
   This rule allows anonymous calls inbound from Teams to the SIP trunking provider.
   

   To add a new action click anywhere in the New Entry bar.
   
   

   1. Configure the parameters in the actions pane.
   2. Configure each Header Value one at a time and click Add before creating the next rule.

   3. Click Update and then click Submit to save the action.
      
      

      Configuring the FromTeams2ServerAnonymous Action

      Parameter		Example Configuration Value
      Name		FromTeams2ServerAnonymous Arbitrary name (alphanumeric characters only)
      Send To	Trunking Device	None
      Prioritize		Not used for MS Teams
      Refer to Re-INVITE		Enabled
      Serial Hunting		Not used for MS Teams
      E.164 Conversion rule		None
      Conversion mode		Add (default)

      Header		Example Value
      Request-URI		'sip:' + substr($request.uri.user, 2, 0) + '@' + $env.available_domain + ':' + $env.available_port
      From		$from.dispname + ' <sip:' + $from.uri.user + '@' + $env.out_intf_host + ':' + $env.out_intf_port + '>'
      To		$to.dispname + ' <sip:' + substr($to.uri.user, 2, 0) + '@' + $env.available_domain + ':' + $env.available_port + '>'
      Contact		$from.dispname + ' <sip:' + $from.uri.user + '@' + $env.out_intf_host + ':' + $env.out_intf_port + '>' + $contact.parameter
      P-Asserted-Identity		$pai?'<sip:' + substr($pai, 7, 10) + '@' + $env.out_intf_host + ':' + $env.out_intf_port + '>'
      Other	Privacy	'id'

8. The third action is “FromTeams2Server”. This rule will have an associated “Match” rule for calls outbound from Teams to the SIP Trunking provider for destination call routing. This example uses a “P-Asserted-Identity” header string which is common to many SIP trunking providers. Please verify with your trunking provider if they require these SIP headers or have other header requirements for interoperability with their SIP service.
   To add a new action click anywhere in the New Entry bar.
   
   
   

   1. Configure the parameters in the actions pane.
      

   2. Configure each Header Value one at a time and click Add before creating the next rule.

   3. Click Update and then click Submit to save the action.
      
      
      

      Configuring the FromTeams2Server Action

      Parameter		Example Configuration Value
      Name		FromTeams2Server Arbitrary name (alphanumeric characters only)
      Send To	Trunking Device	None
      Prioritize		Not used for MS Teams
      Refer to Re-INVITE		Enabled
      Serial Hunting		Not used for MS Teams
      E.164 Conversion rule		None
      Conversion mode		Add (default)

      Header	Example Value
      Request-URI	'sip:' + substr($request.uri.user, 2, 0) + '@' + $env.available_domain + ':' + $env.available_port
      From	$from.dispname + ' <sip:' + substr($from.uri.user, 2, 0) + '@' + $env.out_intf_host + ':' + $env.out_intf_port + '>'
      To	$to.dispname + ' <sip:' + substr($to.uri.user, 2, 0) + '@' + $env.available_domain + ':' + $env.available_port + '>'
      Contact	$from.dispname + ' <sip:' + substr($from.uri.user, 2, 0) + '@' + $env.out_intf_host + ':' + $env.out_intf_port + '>' + $contact.parameter
      P-Asserted-Identity	$pai?'<sip:' + substr($pai, 7, 10) + '@' + $env.out_intf_host + ':' + $env.out_intf_port + '>'
      History-info	$history-info?' <sip:' + replace($history-info.uri.user, '+1', '' ) + '@' + $env.out_intf_host + ':' + $env.out_intf_port + '>;reason=unknown;counter=1'
      History-info	$history-info#1?' <sip:' + replace($history-info#1.uri.user, '+1', '' ) + '@' + $env.out_intf_host + ':' + $env.out_intf_port + '>;reason=unknown;counter=1'

9. Scroll down to the Match pane to configure the patterns you wish to match to the actions just created. The match function provides dial plan routing to Actions and relates to the direction the call is coming from. This could be from Teams or from the SIP trunking provider. The examples given in this section will use a dial plan of 408.555.1000-1099 to provide basic knowledge of how to apply your dial plan to the previously created Actions.
   The example uses a “Redirect” rule from Teams as “+1.”. By default, Teams will add this to the beginning of every outbound call going to the SBC for SIP trunk routing. This rule is mapped to the Action.”FromTeams2Server” will remove the +1 from the SIP message and then perform the other header modifications before forwarding the SIP message to the trunking provider. If you’ve configured Teams to not add the +1, then modify the “FromTeams2Server” Action and other header manipulation rules that reference +1 and remove the reference.
   The +1. (dot ) portion of the string matches one or more digits. This (dot) allows dialed destinations greater than 10 or 11 digits to be called. If international calling is desired, please verify that the MS Teams voice route to the SBC also includes pattern matches to accommodate international calling. 911, 411 and any other dial plans must also be considered as an SBC or MS Teams pattern match to route the call correctly.
   
   

   Note

   Match rules are in order of priority from top to bottom. A specific rule must be above a generic rule.

   
   

   1. The first “Match” rule is for the Teams dial plan assigned by the SIP trunking provider. In this example the DID range for this MS Teams configuration is 408.555.1000-1099.

      1. Configure the parameters in the match pane.
         

      2. Click Update and then click Submit to save the Match.
         
         
         

         Configuring the Called Matches ToTeams Match

         Parameter		Example Configuration Value
         Direction		Redirect
         Mode		BothModes
         Default		Not used for MS Teams
         Pattern		Called
         Called Party	Matches	408555.
         Calling Party	Not Set	NA
         Source		Any
         Action		ToTeams

   2. The second Match rule is to allow the blocked caller ID’s from Teams, which presents as “anonymous” in the SIP header. For example,
      From: "Anonymous"sip:anonymous@anonymous.invalid:5060.
      To add a new action click anywhere in the New Entry bar.
      
      
      

      1. Configure the parameters in the match pane.
         

      2. Click Update and then click Submit to save the Match.
         
         

         Configuring the FromTeams2ServerAnonymous Match

         Parameter		Example Configuration Value
         Direction		Redirect
         Mode		BothModes
         Default		Not used for MS Teams
         Pattern		Both
         Called Party	Matches	+1.
         Calling Party	Does not match	+1.
         Source		TeamsGroup
         Action		FromTeams2ServerAnonymous

   3. The third Match rule is to match +1. SIP messages from MS Teams to the Actions that routes the call to the configured SIP trunking provider, after the header manipulation is performed. This rule is required for normal caller-ID routing.
      To add a new action click anywhere in the New Entry bar.
      
      
      

      1. Configure the parameters in the match pane.
         

      2. Click Update and then click Submit to save the Match.
         
         
         

         Configuring the FromTeams2Server Match

         Parameter		Example Configuration Value
         Direction		Redirect
         Mode		BothModes
         Default		Not used for MS Teams
         Pattern		Both
         Called Party	Matches	+1.
         Calling Party	Matches	+1.
         Source		TeamsGroup
         Action		FromTeams2Server

You have now completed the 

As a final step, save the SBC’s configuration at this point or when you are finished testing.

Saving the ESBC's Configuration

This section discusses how to save the running SBC’s configuration to restore the system back to a known working configuration if required.

1. Choose Admin > Backup/Restore from the Configuration Menu on the left-hand side. 

2. Click Create New Config Backup. A dialog box will appear. Click OK.
   
   

    

3. The system will create a backup file of the current running configuration. Click the file name to download the backup file to the management computer.