update ended reasons doc (#271)

Author: bryantanderson

fern/calls/call-ended-reason.mdx

@@ -4,7 +4,6 @@ subtitle: A guide to understanding all call "Ended Reason" types & errors.
 slug: calls/call-ended-reason
 ---
 
-
 This guide will discuss all possible `endedReason`s for a call.
 
 You can find these under the **"Ended Reason"** section of your [call
@@ -14,6 +13,7 @@ Object](/api-reference/calls/get-call)).
 #### **Assistant-Related**
 
 - **assistant-ended-call**: The assistant intentionally ended the call based on the user's response.
+- **assistant-ended-call-after-message-spoken**: The assistant intentionally ended the call after speaking a pre-defined message.
 - **assistant-error**: This general error occurs within the assistant's logic or processing due to bugs, misconfigurations, or unexpected inputs.
 - **assistant-forwarded-call**: The assistant successfully transferred the call to another number or service.
 - **assistant-join-timed-out**: The assistant failed to join the call within the expected timeframe.
@@ -30,21 +30,24 @@ Object](/api-reference/calls/get-call)).
 
 These relate to issues within the AI processing pipeline or the Large Language Models (LLMs) used for understanding and generating text:
 
-- **pipeline-error-\***: Various error codes indicate specific failures within the processing pipeline, such as function execution, LLM responses, or external service integration. Examples include OpenAI, Azure OpenAI, Together AI, and several other LLMs or voice providers.
-- **pipeline-error-first-message-failed:** The system failed to deliver the first message. This issue usually occurs when you add your own provider key in the voice section. It may be due to exceeding your subscription or quota limit.
-- **pipeline-no-available-llm-model**: No suitable LLM was available to process the request.
+- **call.in-progress.error-vapifault-\***: Various error codes indicate specific failures within the processing pipeline, such as function execution, LLM responses, or external service integration. Examples include OpenAI, Azure OpenAI, Together AI, and several other LLMs or voice providers.
+- **call.in-progress.error-providerfault-\***: Similar to **call.in-progress.error-vapifault-\***. However, these error codes are surfaced when Vapi receives an error that has occured on the provider's side. Examples include internal server errors, or service unavailability.
+- **pipeline-error-\***: Similar to **call.in-progress.error-vapifault-\***. However, these error codes are surfaced when you are using your own provider keys.
+- **pipeline-no-available-llm-model**: No suitable LLM was available to process the request. Previously **pipeline-no-available-model**.
 
 #### **Phone Calls and Connectivity**
 
 - **customer-busy**: The customer's line was busy.
 - **customer-ended-call**: The customer(end human user) ended the call for both inbound and outbound calls.
 - **customer-did-not-answer**: The customer didn't answer the call. If you're looking to build a usecase where you need the bot to talk to automated IVRs, set `assistant.voicemailDetectionEnabled=false`.
 - **customer-did-not-give-microphone-permission**: The user didn't grant the necessary microphone access for the call.
+- **assistant-did-not-receive-customer-audio**: Similar to **customer-did-not-give-microphone-permission**, but more generalized to situations where no customer audio was received.
 - **phone-call-provider-closed-websocket**: The connection with the call provider was unexpectedly closed.
 - **twilio-failed-to-connect-call**: The Twilio service, responsible for managing calls, failed to establish a connection.
 - **vonage-disconnected**: The call was disconnected by Vonage, another call management service.
 - **vonage-failed-to-connect-call**: Vonage failed to establish the call connection.
 - **vonage-rejected**: The call was rejected by Vonage due to an issue or configuration problem.
+- **sip-telephony-provider-failed-to-connect-call**: The SIP telephony provider failed to establish the call connection. Previously **sip-gateway-failed-to-connect-call**.
 
 #### **Other Reasons**