挂机原因值、Q850原因值、呼叫拆线点

调用接口会产生接口调用错误码，详见API错误码处理。

调用接口成功后，如果用户在添加应用时指定了呼叫状态接收地址和呼叫话单接收地址，则隐私保护通话平台在接收到南向网元返回的呼叫状态通知和话单通知时，会主动将呼叫状态通知和话单通知推送给客户。

话单消息示例如下：

POST /fee HTTP/1.1

Content-Length: xx 

{"eventType":"fee","feeLst":[{"direction":1,"spId":"****","appKey":"****","icid":"ba171f34e6953fcd751edc77127748f4.3757285803.338666679.5","bindNum":"+86138****0022","sessionId":"1200_1827_4294967295_20190124023003@callenabler246.huaweicaas.com","subscriptionId":"****","callerNum":"+86138****0021","calleeNum":"+86138****0022","fwdDisplayNum":"+86138****0022","fwdDstNum":"+86138****7021","callInTime":"2019-01-24 02:30:03","fwdStartTime":"2019-01-24 02:30:03","fwdAlertingTime":"2019-01-24 02:30:04","fwdAnswerTime":"2019-01-24 02:30:06","callEndTime":"2019-01-24 02:30:22","fwdUnaswRsn":0,"ulFailReason":0,"sipStatusCode":0,"callOutUnaswRsn":0,"recordFlag":1,"recordStartTime":"2019-01-24 02:30:06","recordDomain":"****.com","recordBucketName":"****","recordObjectName":"****.wav","ttsPlayTimes":0,"ttsTransDuration":0,"mptyId":"****","serviceType":"003","hostName":"callenabler246.huaweicaas.com"}]}

如果某一通呼叫失败，客户可根据平台推送的挂机原因值（stateCode）、转接呼叫操作失败的Q850原因值（fwdUnaswRsn）或通话失败的拆线点（ulFailReason）查询失败原因。

1. 在隐私保护通话平台推送的呼叫状态通知和话单通知中查询该通呼叫的“stateCode”、“fwdUnaswRsn”和“ulFailReason”。
2. 查看附录的挂机原因值、Q850原因值、呼叫拆线点详细说明，判断呼叫失败的原因。

注：“stateCode”请在接收到的呼叫状态通知（disconnect事件）中查看，“fwdUnaswRsn”和“ulFailReason”请在接收到的话单通知中查看。