Updates to SIP response codes from Michal Kebis

Author: Cloud-Writer

Exchange/ExchangeServer/compliance/ediscovery-search-missing-items.md

@@ -15,7 +15,7 @@ ms.reviewer: dpaul
 appliesto: 
   - Exchange Server 2019
 search.appverid: MET150
-ms.date: 01/24/2024
+ms.date: 08/18/2025
 ---
 # Missing items in eDiscovery search results in Exchange Server 2019
 
@@ -46,7 +46,7 @@ In some scenarios, the time stamp information that's passed on to a subsequent p
 
 ## Workaround
 
-To work around this issue, create a setting override to use the **Search Folder** type in the search query setting. The setting override will be retained for 180 days only. To maintain the override, you must re-create it before it expires.
+To work around this issue, create a setting override to use the **Search Folder** type in the search query setting.
 
 1. Run the following cmdlet to create a setting override:
 

Teams/phone-system/direct-routing/microsoft-sip-response-codes-415.md

@@ -0,0 +1,31 @@
+---
+title: SIP 415 and Microsoft response codes
+description: Lists combinations of Microsoft response code and the SIP 415 error, and provides actions to resolve the errors.
+ms.date: 08/18/2025
+author: Cloud-Writer
+ms.author: meerak
+manager: dcscontentpm
+audience: Admin
+ms.topic: troubleshooting
+search.appverid: 
+  - SPO160
+  - MET150
+appliesto: 
+  - Microsoft Teams
+ms.custom: 
+  - sap:Teams Calling (PSTN)\Direct Routing
+  - CI 6328
+  - CSSTroubleshoot
+ms.reviewer: teddygyabaah
+---
+
+# SIP response code 415
+
+This article provides troubleshooting information for the combination of the SIP 415 error and Microsoft response code 510415.
+
+## 540415 415 Unsupported Media Type
+
+- Microsoft response code: **540415**
+- SIP response code: **415**
+- Suggested actions:  
+  - This error indicates that either the SBC offer is missing or it contains an unsupported media type. For example, the CONTENT-TYPE might be missing or the SBC offer has unsupported data such as information about the application, or pidf+xml. Check the SBC configuration to fix the problem.

Teams/phone-system/direct-routing/microsoft-sip-response-codes-420.md

@@ -1,7 +1,7 @@
 ---
 title: SIP 420 and Microsoft response codes
 description: Lists combinations of Microsoft response codes and the SIP 420 error, and provides actions to resolve the errors.
-ms.date: 11/22/2024
+ms.date: 08/18/2025
 author: Cloud-Writer
 ms.author: meerak
 manager: dcscontentpm
@@ -15,13 +15,21 @@ appliesto:
 ms.custom: 
   - sap:Teams Calling (PSTN)\Direct Routing
   - CI2387
+  - CI 6328
   - CSSTroubleshoot
 ms.reviewer: mikebis
 ---
 
 # SIP response code 420
 
-This article provides troubleshooting information for the combination of the SIP 420 error and Microsoft response code 560420.
+This article provides troubleshooting information for the combination of the SIP 420 error and various Microsoft response codes.
+
+## 540420 420 Bad Extension
+
+- Microsoft response code: **540420**
+- SIP response code: **420**
+- Suggested actions:  
+  - Check the SBC configuration to make sure that it doesn't require an unsupported SIP protocol extension such as REQUIRE : 100rel. SIP messages usually contain information about extensions that aren't supported. If necessary, work with your SBC vendor to verify that the SBC is configured correctly to provide the required SIP protocol extension.
 
 ## 560420 420 Bad Extension
 

Teams/phone-system/direct-routing/microsoft-sip-response-codes-422.md

@@ -0,0 +1,32 @@
+---
+title: SIP 422 and Microsoft response codes
+description: Lists combinations of Microsoft response codes and the SIP 422 error, and provides actions to resolve the errors.
+ms.date: 08/18/2025
+author: Cloud-Writer
+ms.author: meerak
+manager: dcscontentpm
+audience: Admin
+ms.topic: troubleshooting
+search.appverid: 
+  - SPO160
+  - MET150
+appliesto: 
+  - Microsoft Teams
+ms.custom: 
+  - sap:Teams Calling (PSTN)\Direct Routing
+  - CI 6328
+  - CSSTroubleshoot
+ms.reviewer: mikebis
+---
+
+# SIP response code 422
+
+This article provides troubleshooting information for the combination of the SIP 422 error and Microsoft response code 540422.
+
+## 540422 422 Session Interval Too Small
+
+- Microsoft response code: **540422**
+- SIP response code: **422**
+- Suggested actions:  
+  - Check the SBC configuration to make sure that the SBC re-invites as per the RFC to avoid call failures when the session interval is too small.  
+  - If you see many calls with this call end reason or a sub-reason, consider increasing either both the Session Timer and Minimum Session Timer or one of them in the SBC configuration.

Teams/phone-system/direct-routing/microsoft-sip-response-codes-480.md

@@ -20,7 +20,7 @@ ms.reviewer: teddygyabaah
 
 # SIP response code 480
 
-This article provides troubleshooting information for various combinations of the SIP "480" error and Microsoft response codes.
+This article provides troubleshooting information for various combinations of the SIP "480" error and various Microsoft response codes.
 
 ## 10037 480 No callee endpoints were found
 

Teams/phone-system/direct-routing/microsoft-sip-response-codes-488.md

@@ -20,7 +20,7 @@ ms.reviewer: teddygyabaah
 
 # SIP response code 488
 
-This article provides troubleshooting information for various combinations of the SIP 488 error and Microsoft response codes.
+This article provides troubleshooting information for various combinations of the SIP 488 error and various Microsoft response codes.
 
 ## 531000 488 InternalDiagCode: CannotSupportAnyMedia, InternalErrorPhrase: Invalid SDP offer: no media acceptable
 

Teams/phone-system/direct-routing/microsoft-sip-response-codes-500.md

@@ -1,7 +1,7 @@
 ---
 title: SIP 500 and Microsoft response codes
 description: Lists combinations of Microsoft response code and the SIP 500 error, and provides actions to resolve the errors.
-ms.date: 10/30/2023
+ms.date: 08/18/2025
 author: Cloud-Writer
 ms.author: meerak
 manager: dcscontentpm
@@ -14,14 +14,15 @@ appliesto:
   - Microsoft Teams
 ms.custom: 
   - sap:Teams Calling (PSTN)\Direct Routing
-  - CI173631
+  - CI 173631
+  - CI 6328
   - CSSTroubleshoot
-ms.reviewer: teddygyabaah
+ms.reviewer: teddygyabaah; mikebis
 ---
 
 # SIP response code 500
 
-This article provides troubleshooting information for various combinations of the SIP 500 error and Microsoft response codes.
+This article provides troubleshooting information for various combinations of the SIP 500 error and various Microsoft response codes.
 
 ## 510482 500 Loop detected
 
@@ -43,3 +44,17 @@ This article provides troubleshooting information for various combinations of th
 - SIP response code: **500**
 - Suggested actions:  
   - Review the [emergency call routing policies](/microsoftteams/manage-emergency-call-routing-policies) and fix any misconfiguration.
+
+## 540500 500 Internal Server Error - Transfer call without draft call data
+
+- Microsoft response code: **540500**
+- SIP response code: **500**
+- Suggested actions:  
+  - This error often occurs in transfer scenarios when a customer’s SBC sends duplicate INVITEs in response to Microsoft REFER after the initial INVITE request is rejected. The SBC shouldn't send an INVITE again in response to the rejected request but should send the NOTIFY that contains the reason for the rejection. Then Microsoft will either send a new REFER, or indicate that the transfer failed in the Teams client.
+
+## 540500 500 Internal Server Error - Duplicate CreateCallAsync request
+
+- Microsoft response code: **510544**
+- SIP response code: **500**
+- Suggested actions:  
+  - The customer's SBC sends duplicate INVITE requests to Microsoft, and Microsoft declines the latest one. The SBC shouldn't send multiple duplicate requests.

Teams/phone-system/direct-routing/microsoft-sip-response-codes-503.md

@@ -20,7 +20,7 @@ ms.reviewer: teddygyabaah
 
 # SIP response code 503
 
-This article provides troubleshooting information for various combinations of the SIP 503 error and Microsoft response codes.
+This article provides troubleshooting information for various combinations of the SIP 503 error and various Microsoft response codes.
 
 ## 10320 503 Bot is unreachable or unable to answer before timeout
 

Teams/phone-system/direct-routing/microsoft-sip-response-codes-504.md

@@ -20,7 +20,7 @@ ms.reviewer: teddygyabaah
 
 # SIP response code 504
 
-This article provides troubleshooting information for various combinations of the SIP 504 error and Microsoft response codes.
+This article provides troubleshooting information for various combinations of the SIP 504 error and various Microsoft response codes.
 
 ## 549002 504 Unable to deliver INVITE: TlsTransport is not connected, State=Disconnected
 

Teams/phone-system/direct-routing/microsoft-sip-response-codes.md

@@ -16,8 +16,9 @@ ms.custom:
   - sap:Teams Calling (PSTN)\Direct Routing
   - CI166247
   - CI173631
+  - CI 6328
   - CSSTroubleshoot
-ms.reviewer: rishire, teddygyabaah
+ms.reviewer: rishire, teddygyabaah, mikebis
 ---
 
 # Microsoft and SIP response codes
@@ -45,11 +46,13 @@ For more information about the most common errors and suggested actions to furth
 - [408 Request Timeout](./microsoft-sip-response-codes-408.md)
 - [410 Gone](./microsoft-sip-response-codes-410.md)
 - [412 Conditional Request Failed](./microsoft-sip-response-codes-412.md)
+- [415 Unsupported Media Type](./microsoft-sip-response-codes-415.md)
 - [420 Bad Extension](./microsoft-sip-response-codes-420.md)
+- [422 Session Interval Too Small](./microsoft-sip-response-codes-422.md)
 - [480 Temporarily Unavailable](./microsoft-sip-response-codes-480.md)
 - [484 Address Incomplete](./microsoft-sip-response-codes-484.md)
 - [486 Busy Here](./microsoft-sip-response-codes-486.md)
 - [488 Not Acceptable Here](./microsoft-sip-response-codes-488.md)
-- [500 Server Internal Error](./microsoft-sip-response-codes-500.md)
+- [500 Internal Server Error](./microsoft-sip-response-codes-500.md)
 - [503 Service Unavailable](./microsoft-sip-response-codes-503.md)
 - [504 Server Time-out](./microsoft-sip-response-codes-504.md)