WarmTransfer
sbc trunking · published

AudioCodes Mediant SBC

Verified 2026-09-24 · 60 sources · tier 2

Also known as AudioCodes SBC, Mediant SBC.

The AudioCodes Mediant SBC routes and manipulates SIP sessions between IP entities across enterprise and service provider networks 37​8. Its software line is documented across Mediant VE (Virtual Edition), Mediant CE (Cloud Edition), and Mediant SE (Server Edition) 44.

Signaling and Network Architecture

A Mediant SIP Interface represents a Layer-3 network by defining a local listening port and transport type, and assigns an IP network interface for SIP signaling 42. Each SIP Interface associates with only 1 SRD, and in single-SRD deployments, SIP Interfaces assign to the default SRD automatically 43. At least 1 SIP Interface must be assigned to a Proxy Set 36.

An IP Group represents a SIP entity the device communicates with, such as a server (IP PBX or ITSP) or a group of users (LAN IP phones) 8. Mediant IP Groups have 3 types: Server (address known, usually through a Proxy Set), User (location learned from REGISTER), and Gateway (SBC only; address taken from the Contact header of the gateway's REGISTER) 13.

For Server-type IP Groups, INVITE messages destined to the IP Group are sent to the address configured in its associated Proxy Set 12. Topology hiding can be applied via the SIP Group Name parameter, which overwrites the host part of the URI in certain SIP headers for source and destination IP Groups 40. The Media Realm assigned to an IP Group determines the UDP port range and maximum number of media sessions on a specific IP interface for that group's media 11.

An IP Profile defines signaling and media parameters—such as REFER handling and coders—that take effect when assigned to IP Groups 14. Within an IP Profile, the SBC Media Security Mode defaults to As is (no special RTP/SRTP handling), with other options being Secured, Not Secured, and Both 25. The ICE Mode parameter can be set to Lite to enable ICE for the associated SIP user agent 15.

Proxy Sets and Keep-Alives

A Proxy Set defines the address (IP address or FQDN) and transport type (such as UDP or TCP) of a SIP server 28. FQDNs configured in Proxy Sets can be resolved by A-record (the default), SRV, NAPTR, or a Microsoft Skype for Business method 30.

Proxy Set keep-alive methods include SIP OPTIONS, REGISTER, OPTIONS sent only to the active server, or a "fake REGISTER" expecting a 404 response 32. The Proxy Keep-Alive Time defaults to 60 seconds (configurable from 5 to 2,000,000 seconds) 31. To mark an offline proxy online again, the Success Detection Retries setting requires consecutive successful keep-alives ranging from 1 to 100 (default 1) 29. If an IP Group enables Proxy Keep-Alive using IP Group settings, its Outbound Manipulation Set also applies to proxy keep-alive SIP OPTIONS messages 17.

In Parking redundancy mode the SBC stays with the current proxy until it fails; in Homing mode it always tries to use the highest-priority proxy currently online 35. Load balancing is disabled by default, with available options of Round Robin or Random Weights (traffic distributed by configured weights) 33.

Dialog Classification and Call Routing

To classify an incoming dialog to a source IP Group, the SBC checks, in order, the users registration database, then the Proxy Set (by source address), then the Classification table 3. AudioCodes recommends classifying SIP dialogs by Proxy Set for security only when the IP Group's address is unknown, meaning the Proxy Set uses an FQDN 4.

Classification rules support an Action Type of Allow (whitelist: assigns the dialog to the rule's IP Group) or Deny (blacklist: blocks the dialog) 1. If no Classification rule matches, the SBC rejects or allows the call depending on the configured classification-failure action 2. The SIP Interface Classification Failure Response Type parameter defines the SIP response code sent when classification fails; it defaults to 500, accepts values from 400 to 699, and can be set to 0 to send no response against DoS attacks 41.

The SBC searches the IP-to-IP Routing table from top to bottom and uses the first rule that matches the incoming call 37. If no rule matches, the SBC rejects the call 38. AudioCodes advises placing stricter routing rules higher in the table than less strict rules 39.

Message Manipulation

Message Manipulation rules can add, remove, or modify SIP headers, header parameters, and message bodies, translate response codes, and support topology hiding, running sequentially on a message 20. Message manipulation can run before classification by assigning a Manipulation Set to the SIP Interface, applying only to incoming dialog-initiating requests rather than in-dialog messages 27. Each IP Group can be assigned an Inbound Message Manipulation Set and an Outbound Message Manipulation Set, applied to SIP messages on the respective call leg 9.

Each rule defines a Row Role set to either Use Current Condition (evaluates its own condition) or Use Previous Condition (reuses the condition of the nearest earlier rule set to Use Current Condition) 22. Syntax for conditions and actions is documented separately in the AudioCodes SIP Message Manipulation Reference Guide 23.

Capacity and Platform Limits

Feature Low-RAM VE/CE High-RAM VE/CE Mediant SE
Max IP Groups 1,500 10 5,000 (32–64 GB) 10 5,000 10
Max Proxy Set Addresses 10 (2–16 GB) 34 50 (32–64 GB) 34 50 34
Total Message Manipulation Rules 750 (2–8 GB) / 1,000 (16 GB) 21 5,000 (32–64 GB) 21 5,000 21

Diagnostics and Debugging

The Mediant SBC acts as a syslog client, sending error, warning, and system event messages to external syslog servers 45. Syslog is enabled in the Web interface via the Enable Syslog check box under Troubleshoot menu > Troubleshoot tab > Logging folder > Logging Settings 46.

Debug recording duplicates inbound and outbound messages (such as SIP, RTP/RTCP, and T.38) and forwards them to an external debug capturing server 5. It is activated by a logging filter rule with Log Destination set to Debug Recording 6. Syslog messages can also be included in debug recording via logging filter rules 47.

The Logging Filters table holds up to 60 rules, filtering by criteria including Any, IP Group, SRD, Classification, IP-to-IP Routing, User, SIP Interface, or IP Trace 19. Log destinations comprise syslog servers, debug recording servers, local device storage, or OVOC (for quality-of-experience data), using log types Signaling, Signaling & Media, or Signaling & Media & PCM 18. AudioCodes warns that media debug recording consumes significant device resources; when many media sessions are selected, not all sessions and their signaling will be recorded 24.

Microsoft Teams Direct Routing Integration

Microsoft's certified Direct Routing SBC list includes the AudioCodes Mediant 500, 500 Li, 800, 1000B, 2600, 3100, 4000, 7000, and 9000 hardware appliances, alongside Virtual Edition and Mediant Cloud Edition 51. All listed models are certified for both non-media-bypass and media bypass 51. Local Media Optimization (LMO) is supported on Mediant 500, 800, 1000B, 2600, 4000, 9000, Virtual Edition, and Cloud Edition 52.

For most AudioCodes models, Microsoft lists firmware Supported 7.40A.600 (Recommended 7.40A.500) 49. Mediant 500 Li lists Supported 7.2x.xxx (Recommended 7.40A.400), and Mediant 7000 lists Recommended 7.40A.600 49. For LMO, most models list Supported 7.20A.258 (Recommended 7.40A.100), while Mediant 500 lists 7.20A.256 52. Microsoft supports firmware versions higher than documented provided the major.minor release remains identical 50. Microsoft states it is not accepting new nominations for Direct Routing SBC certification until further notice 54. For Direct Routing issues, customers must contact the SBC vendor's support first, and escalations to Microsoft require the vendor's investigation report 60.

Direct Routing connectivity requires specific signaling, security, and media parameters:

  • Signaling FQDNs: For Microsoft 365, Office 365 and GCC, an SBC connects to Direct Routing through sip.pstnhub.microsoft.com, sip2.pstnhub.microsoft.com, and sip3.pstnhub.microsoft.com in that priority order 58.
  • Ports & Transport: SIP/TLS outbound to Microsoft on destination port 5061; inbound from Microsoft uses the SBC's configured port 57. Microsoft forces TLS 1.2 and requires SBC support for 4 specific ECDHE-RSA AES cipher suites 59.
  • Media Ports: Direct Routing media between Microsoft media processors and the SBC uses UDP/SRTP on ports 3478 to 3481 and 49152 to 53247, and Microsoft recommends at least 2 SBC media ports per concurrent call 53.
  • Keep-Alive Validation: Validated when the SBC receives 200 OK to its outgoing OPTIONS and replies 200 OK to inbound OPTIONS sent by Direct Routing to the Contact header FQDN of the SBC's OPTIONS 56.

AudioCodes Live Platform documentation provides Direct Routing SBC configuration templates for single-tenant enterprise and multitenant deployments 7.

See also

Applicability

Applies to: AudioCodes Mediant Software SBC, AudioCodes Mediant SBC, Microsoft Teams Phone Direct Routing, and AudioCodes Live Platform. Deployments: on-premises, multi-tenant, cloud-iaas, single-tenant, and virtual. Sources checked 2026-09-24. For Microsoft Teams Direct Routing certification, covered firmware versions include 7.20A.256, 7.20A.258, 7.2x.xxx, 7.40A.100, 7.40A.400, 7.40A.500, and 7.40A.600 49​52.

What remains uncertain

The specific syntax and expressions for conditions and actions within Message Manipulation rules are not covered by the sources below. The exact 4 ECDHE-RSA AES cipher suites required by Microsoft for Direct Routing TLS 1.2 are not covered by the sources below.

See also

Alternative to

Depends on

Related to

Referenced by

Sources

  1. 1
    Classification rules take an Action Type of Allow (whitelist: assign the dialog to the rule's IP Group) or Deny (blacklist: block the dialog).
    Configuring Classification Rules (Mediant Software SBC User's Manual Version 7.6) · Configuring Classification Rules, 'Action Type' parameter · Checked 2026-09-24
  2. 2
    If no Classification rule matches, the SBC rejects or allows the call depending on configuration (the classification-failure action setting).
    Configuring Classification Rules (Mediant Software SBC User's Manual Version 7.6) · Configuring Classification Rules, cross-reference to 'Configuring Action for Classification Failure' · Checked 2026-09-24
  3. 3
    To classify an incoming dialog to a source IP Group, the SBC checks, in order, the users registration database, then the Proxy Set (by source address), then the Classification table.
    Configuring Classification Rules (Mediant Software SBC User's Manual Version 7.6) · Configuring Classification Rules, classification process description · Checked 2026-09-24
  4. 4
    For security, AudioCodes recommends classifying SIP dialogs by Proxy Set only when the IP Group's address is unknown, meaning its Proxy Set is configured with an FQDN.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, 'Classify By Proxy Set' parameter note · Checked 2026-09-24
  5. 5
    When debug recording is active, the SBC duplicates the messages it sends and receives (for example SIP, RTP/RTCP and T.38) and forwards the copies to an external debug capturing server.
    Syslog and Debug Recording (Mediant Software SBC User's Manual Version 7.6) · Syslog and Debug Recording, debug recording paragraph · Checked 2026-09-24
  6. 6
    Debug recording is activated through a logging filter rule whose Log Destination is set to 'Debug Recording'.
    Configuring Debug Recording (Mediant Software SBC User's Manual Version 7.6) · Configuring Debug Recording, overview and child-section list · Checked 2026-09-24
  7. 7
    AudioCodes Live Platform documentation provides Direct Routing SBC configuration templates for a single-tenant enterprise deployment and a multitenant deployment, to be modified to suit each site.
    Direct Routing SBC Configuration Templates · Direct Routing SBC Configuration Templates, page body · Checked 2026-09-24
  8. 8
    On a Mediant SBC, an IP Group represents a SIP entity the device communicates with, either a server such as an IP PBX or ITSP, or a group of users such as LAN IP phones.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, opening paragraph · Checked 2026-09-24
  9. 9
    Each IP Group can be assigned an Inbound Message Manipulation Set and an Outbound Message Manipulation Set, applied to SIP messages on the respective call leg.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, 'Inbound Message Manipulation Set' and 'Outbound Message Manipulation Set' parameters · Checked 2026-09-24
  10. 10
    Mediant Software SBC supports up to 5,000 IP Groups on Mediant SE and on VE/CE with 32 to 64 GB RAM, and up to 1,500 IP Groups on lower-RAM VE/CE instances.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, note on maximum number of IP Groups · Checked 2026-09-24
  11. 11
    The Media Realm assigned to an IP Group determines the UDP port range and maximum number of media sessions on a specific IP interface for that IP Group's media.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, 'Media Realm' parameter description · Checked 2026-09-24
  12. 12
    For a Server-type IP Group, INVITE messages destined to the IP Group are sent to the address configured in the Proxy Set associated with that IP Group.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, 'Proxy Set' parameter description · Checked 2026-09-24
  13. 13
    Mediant IP Groups have three types: Server (address known, usually through a Proxy Set), User (location learned from REGISTER), and Gateway (SBC only; address taken from the Contact header of the gateway's REGISTER).
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, 'Type' parameter description · Checked 2026-09-24
  14. 14
    An IP Profile is a set of signaling and media parameters (for example REFER handling and coders) that takes effect for calls when assigned to IP Groups.
    Configuring IP Profiles (Mediant Software SBC User's Manual Version 7.6) · Configuring IP Profiles, opening paragraph · Checked 2026-09-24
  15. 15
    The IP Profile has an ICE Mode parameter that can be set to Lite, enabling ICE for the SIP user agent associated with that IP Profile.
    Configuring IP Profiles (Mediant Software SBC User's Manual Version 7.6) · Configuring IP Profiles, 'ICE Mode' parameter · Checked 2026-09-24
  16. 16
    The Mediant default Proxy Keep-Alive Time of 60 seconds sits exactly at Microsoft's upper bound of one OPTIONS every 60 seconds, so the default appears compliant, but any lower setting would exceed the limit.inferred
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, 'Proxy Keep-Alive Time'; compared with ms-learn-dr-connect-sbc Considerations · Checked 2026-09-24
  17. 17
    When the IP Group's 'Proxy Keep-Alive using IP Group settings' option is enabled, the IP Group's Outbound Manipulation Set is also applied to the proxy keep-alive SIP OPTIONS messages.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, 'Proxy Keep-Alive using IP Group settings' parameter · Checked 2026-09-24
  18. 18
    A logging filter can send its output to a syslog server, a debug recording server, local storage on the device, or OVOC (for quality-of-experience data), with log types of Signaling, Signaling & Media, or Signaling & Media & PCM.
    Configuring Log Filter Rules (Mediant Software SBC User's Manual Version 7.6) · Configuring Log Filter Rules, 'Log Destination' and 'Log Type' parameters · Checked 2026-09-24
  19. 19
    The Logging Filters table holds up to 60 rules, and filters can target calls by criteria such as Any, IP Group, SRD, Classification, IP-to-IP Routing, User, SIP Interface or IP Trace.
    Configuring Log Filter Rules (Mediant Software SBC User's Manual Version 7.6) · Configuring Log Filter Rules, table limit note and 'Filter Type' parameter · Checked 2026-09-24
  20. 20
    Message Manipulation rules can add, remove or modify SIP headers, header parameters and message bodies, translate response codes, and support topology hiding; several rules can apply to the same message in sequence.
    Configuring SIP Message Manipulation (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Message Manipulation, opening list of manipulation capabilities · Checked 2026-09-24
  21. 21
    The Mediant Software SBC allows 750 Message Manipulation rules in total on 2 to 8 GB VE/CE, 1,000 on 16 GB VE/CE, and 5,000 on Mediant SE and 32 to 64 GB VE/CE.
    Configuring SIP Message Manipulation (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Message Manipulation, 'Child table - Message Manipulations' note · Checked 2026-09-24
  22. 22
    A Message Manipulation rule's Row Role is either 'Use Current Condition' (evaluate its own condition) or 'Use Previous Condition' (reuse the condition of the nearest earlier rule set to Use Current Condition).
    Configuring SIP Message Manipulation (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Message Manipulation, 'Row Role' parameter · Checked 2026-09-24
  23. 23
    The syntax for Message Manipulation conditions and actions is documented in a separate AudioCodes SIP Message Manipulation Reference Guide, not in the User's Manual.
    Configuring SIP Message Manipulation (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Message Manipulation, reference-guide cross-reference · Checked 2026-09-24
  24. 24
    AudioCodes warns that media debug recording needs a lot of device resources and that, when many media sessions are selected, not all sessions and their signaling will be recorded.
    Configuring Log Filter Rules (Mediant Software SBC User's Manual Version 7.6) · Configuring Log Filter Rules, notes on media recording · Checked 2026-09-24
  25. 25
    The IP Profile 'SBC Media Security Mode' defaults to 'As is', which does no special RTP/SRTP handling; the other values are Secured, Not Secured and Both.
    Configuring IP Profiles (Mediant Software SBC User's Manual Version 7.6) · Configuring IP Profiles, 'SBC Media Security Mode' parameter · Checked 2026-09-24
  26. 26
    Message manipulation assigned through IP Groups is post-classification and runs only after classification, number manipulation and routing.
    Configuring SIP Message Manipulation (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Message Manipulation, 'Post-classification' bullet and the general notes · Checked 2026-09-24
  27. 27
    Message manipulation can run before classification by assigning a Manipulation Set to the SIP Interface; it applies only to incoming dialog-initiating requests, not in-dialog messages.
    Configuring SIP Message Manipulation (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Message Manipulation, 'Pre-classification' bullet · Checked 2026-09-24
  28. 28
    A Mediant Proxy Set defines the address (IP address or FQDN) and transport type (for example UDP or TCP) of a SIP server such as a proxy or registrar.
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, opening paragraph · Checked 2026-09-24
  29. 29
    The Proxy Set 'Success Detection Retries' parameter (range 1 to 100, default 1) sets how many consecutive successful keep-alives are needed before an offline proxy is treated as online again.
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, 'Success Detection Retries' parameter · Checked 2026-09-24
  30. 30
    Proxy Set FQDNs can be resolved by A-record (the default), SRV, NAPTR or a Microsoft Skype for Business method.
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, 'DNS Resolve Method' parameter · Checked 2026-09-24
  31. 31
    The Proxy Set 'Proxy Keep-Alive Time' defaults to 60 seconds and can be set from 5 to 2,000,000 seconds.
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, 'Proxy Keep-Alive Time' parameter · Checked 2026-09-24
  32. 32
    Proxy Set keep-alive can use SIP OPTIONS, REGISTER, OPTIONS sent only to the active server, or a 'fake REGISTER' that expects a 404 response.
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, 'Proxy Keep-Alive' parameter values · Checked 2026-09-24
  33. 33
    Proxy Set load balancing is disabled by default and can be set to Round Robin or Random Weights (traffic distributed by each proxy's configured weight).
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, 'Load-Balancing Method' parameter · Checked 2026-09-24
  34. 34
    A Proxy Set can hold up to 10 addresses on Mediant VE/CE with 2 to 16 GB RAM, and up to 50 on Mediant SE and on VE/CE with 32 to 64 GB.
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, note on maximum addresses per Proxy Set · Checked 2026-09-24
  35. 35
    In Parking redundancy mode the SBC stays with the current proxy until it fails; in Homing mode it always tries to use the highest-priority proxy currently online.
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, 'Redundancy Mode' parameter · Checked 2026-09-24
  36. 36
    At least one SIP Interface must be assigned to a Proxy Set.
    Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6) · Configuring Proxy Sets, SIP Interface parameter note · Checked 2026-09-24
  37. 37
    The Mediant SBC searches the IP-to-IP Routing table from top to bottom and uses the first rule that matches the incoming call.
    Configuring SBC IP-to-IP Routing Rules (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring SBC IP-to-IP Routing Rules, introductory paragraphs · Checked 2026-09-24
  38. 38
    If no IP-to-IP Routing rule matches an incoming call, the Mediant SBC rejects the call.
    Configuring SBC IP-to-IP Routing Rules (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring SBC IP-to-IP Routing Rules, introductory paragraphs · Checked 2026-09-24
  39. 39
    AudioCodes advises placing stricter IP-to-IP Routing rules higher in the table than less strict rules.
    Configuring SBC IP-to-IP Routing Rules (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring SBC IP-to-IP Routing Rules, note on rule order · Checked 2026-09-24
  40. 40
    The IP Group 'SIP Group Name' parameter provides topology hiding by overwriting the host part of the URI in certain SIP headers for both source and destination IP Groups.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Configuring IP Groups, 'SIP Group Name' parameter description · Checked 2026-09-24
  41. 41
    The SIP Interface 'Classification Failure Response Type' sets the SIP response sent when classification fails; the default is 500, valid values are 400 to 699, and 0 sends no response, which helps against DoS.
    Configuring SIP Interfaces (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Interfaces, 'Classification Failure Response Type' parameter · Checked 2026-09-24
  42. 42
    A SIP Interface represents a Layer-3 network by defining a local listening port and transport type and assigning an IP network interface for SIP signaling.
    Configuring SIP Interfaces (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Interfaces, opening paragraph · Checked 2026-09-24
  43. 43
    Each SIP Interface can be associated with only one SRD; in single-SRD deployments SIP Interfaces go to the default SRD automatically.
    Configuring SIP Interfaces (Mediant Software SBC User's Manual Version 7.6) · Configuring SIP Interfaces, SRD parameter note · Checked 2026-09-24
  44. 44
    AudioCodes documents Mediant VE (Virtual Edition), Mediant CE (Cloud Edition) and Mediant SE (Server Edition) together in one 'Mediant Software SBC' User's Manual, version 7.6.
    Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6) · Page header: manual title 'Mediant Software (VE, CE and SE) Session Border Controller User's Manual Version 7.6' · Checked 2026-09-24
  45. 45
    The Mediant SBC acts as a syslog client, sending error, warning and system event messages to external syslog servers.
    Syslog and Debug Recording (Mediant Software SBC User's Manual Version 7.6) · Syslog and Debug Recording, syslog paragraph · Checked 2026-09-24
  46. 46
    In the Web interface, syslog is enabled with the 'Enable Syslog' check box on the Logging Settings page (Troubleshoot menu > Troubleshoot tab > Logging folder > Logging Settings).
    Enabling Syslog (Mediant Software SBC User's Manual Version 7.6) · Enabling Syslog, procedure step 1 · Checked 2026-09-24
  47. 47
    Syslog messages can be included in debug recording by configuring logging filter rules.
    Syslog and Debug Recording (Mediant Software SBC User's Manual Version 7.6) · Syslog and Debug Recording, closing sentence · Checked 2026-09-24
  48. 48
    Microsoft's certified-SBC table names 7.40A firmware for AudioCodes, not 7.60A, and its major.minor rule does not on its own extend certification to 7.6; whether 7.6 is certified is unresolved on this evidence.inferred
    Session Border Controllers certified for Direct Routing - Microsoft Teams · Certified SBC vendors table, AudioCodes rows, read together with the firmware-version note · Checked 2026-09-24
  49. 49
    For most AudioCodes models, Microsoft's certified-SBC table lists firmware 'Supported 7.40A.600 (Recommended 7.40A.500)'; Mediant 500 Li is listed as Supported 7.2x.xxx (Recommended 7.40A.400) and Mediant 7000 as Recommended 7.40A.600.
    Session Border Controllers certified for Direct Routing - Microsoft Teams · Certified SBC vendors table, AudioCodes rows, 'Software version' column · Checked 2026-09-24
  50. 50
    Microsoft supports certified SBC firmware versions higher than the documented one as long as the major.minor version is the same.
    Session Border Controllers certified for Direct Routing - Microsoft Teams · Introductory note on firmware versions, above the certified vendor table · Checked 2026-09-24
  51. 51
    Microsoft's certified Direct Routing SBC table lists AudioCodes Mediant 500, 500 Li, 800, 1000B, 2600, 3100, 4000, 7000 and 9000 SBCs plus Virtual Edition and Mediant Cloud Edition, all certified for both non-media-bypass and media bypass.
    Session Border Controllers certified for Direct Routing - Microsoft Teams · Certified SBC vendors table, AudioCodes rows · Checked 2026-09-24
  52. 52
    Microsoft lists AudioCodes Mediant 500, 800, 1000B, 2600, 4000, 9000, Virtual Edition and Cloud Edition SBCs as supporting Local Media Optimization; for most models the table shows Supported 7.20A.258 (Recommended 7.40A.100), and for Mediant 500 it shows 7.20A.256.
    Session Border Controllers certified for Direct Routing - Microsoft Teams · Support for Local Media Optimization table, AudioCodes rows · Checked 2026-09-24
  53. 53
    Direct Routing media between Microsoft media processors and the SBC uses UDP/SRTP on ports 3478 to 3481 and 49152 to 53247, and Microsoft recommends at least two SBC media ports per concurrent call.
    Plan Direct Routing · Media ports table and following tip · Checked 2026-09-24
  54. 54
    Microsoft states it is not accepting new nominations for Direct Routing SBC certification until further notice.
    Session Border Controllers certified for Direct Routing - Microsoft Teams · Paragraph directly above 'Certified SBC vendors' · Checked 2026-09-24
  55. 55
    Microsoft's Connect-the-SBC page says SIP OPTIONS pings must not be sent more often than one transaction every 60 seconds per configured trunk per endpoint; the page's companion 180-second clause is garbled.
    Connect your Session Border Controller (SBC) to Direct Routing · Connect the SBC to the tenant > Considerations, SIP OPTIONS bullet · Checked 2026-09-24
  56. 56
    To validate Direct Routing pairing, the SBC should receive 200 OK to its outgoing OPTIONS and answer Direct Routing's OPTIONS with 200 OK; Direct Routing sends its OPTIONS to the FQDN in the Contact header of the SBC's OPTIONS.
    Connect your Session Border Controller (SBC) to Direct Routing · Verify the SBC connection > Validate SIP options · Checked 2026-09-24
  57. 57
    The SBC sends SIP/TLS to the Microsoft SIP proxy on port 5061; the port the Microsoft proxy uses toward the SBC is the one configured for the SBC.
    Plan Direct Routing · SIP signaling ports table · Checked 2026-09-24
  58. 58
    For Microsoft 365, Office 365 and GCC, an SBC connects to Direct Routing through sip.pstnhub.microsoft.com, sip2.pstnhub.microsoft.com and sip3.pstnhub.microsoft.com in that priority order.
    Plan Direct Routing · SIP signaling: FQDNs · Checked 2026-09-24
  59. 59
    Microsoft forces TLS 1.2 on the Direct Routing SIP interface and lists four ECDHE-RSA AES cipher suites the SBC must be able to use.
    Connect your Session Border Controller (SBC) to Direct Routing · Connect the SBC to the tenant > Considerations, TLS bullet · Checked 2026-09-24
  60. 60
    For Direct Routing issues, the customer must contact the certified SBC vendor's support first, and escalations to Microsoft need the vendor's investigation report.
    Session Border Controllers certified for Direct Routing - Microsoft Teams · Note under the introductory list · Checked 2026-09-24

Documents

tier 2 current vendor documentation

Configuring Classification Rules (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Configuring Debug Recording (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Configuring IP Groups (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Configuring IP Profiles (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Configuring Log Filter Rules (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Configuring Proxy Sets (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Configuring SBC IP-to-IP Routing Rules (Mediant Software (VE, CE and SE) SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Configuring SIP Interfaces (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Configuring SIP Message Manipulation (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Connect your Session Border Controller (SBC) to Direct Routing

Microsoft · 2026-04-26 · accessed 2026-09-21

tier 2 current vendor documentation

Direct Routing SBC Configuration Templates

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Enabling Syslog (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

tier 2 current vendor documentation

Plan Direct Routing

Microsoft (Microsoft Learn) · 2026-08-21 · accessed 2026-09-06

tier 2 current vendor documentation

Session Border Controllers certified for Direct Routing - Microsoft Teams

Microsoft · 2026-05-27 · accessed 2026-09-14

tier 2 current vendor documentation

Syslog and Debug Recording (Mediant Software SBC User's Manual Version 7.6)

AudioCodes · accessed 2026-09-24

Cite this page

APA

WarmTransfer. (2026, September 24). AudioCodes Mediant SBC. WarmTransfer. https://warmtransfer.net/knowledge/audiocodes-mediant-sbc

BibTeX

@misc{warmtransfer-audiocodes-mediant-sbc,
  title  = {AudioCodes Mediant SBC},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/audiocodes-mediant-sbc},
  note   = {Verified 2026-09-24}
}