PDU会话建立拒绝时，SMF如何设置5GSM Cause_

思科SMF对5GSM Cause参数的处理

这个是对照表，在pdu会话建立拒绝时，smf会根据这个表的场景来设置原因值。

来看中英文对照（已经过人工校对，确认是准确的。）

If the connectivity with the requested DN is rejected by the network, SMF sets the 5GSM cause IE of the

PDU Session Establishment Reject message to indicate the reason for rejecting the PDU Session

Establishment procedure.

如果网络拒绝了与请求的DN的连接，SMF会在PDU会话建立拒绝消息中设置5GSM原因信息元素

（IE），以指明拒绝PDU会话建立过程的原因。

The SMF supports the following causes in the PDU Session Establishment Reject message.

SMF支持在PDU会话建立拒绝消息中包含以下原因。

Cause #26 – insufficient resources

原因#26 – 资源不足

The SMF includes this cause when it receives N2SmInfoType with "PDU_RES_SETUP_FAIL" along

with any of the following N2 causes:

当SMF接收到带有“PDU_RES_SETUP_FAIL”的N2SmInfoType以及以下任一N2原因时，会包含此原因：

- RadioNetwork/Radio_resources_not_available

无线网络/无线资源不可用

- RadioNetwork/Failure_in_the_radio_interface_procedure

无线网络/无线接口过程失败

- Misc/Not_enough_user_plane_processing_resources

其他/用户面处理资源不足

也就是说，思科SMF在设置cause26时，是根据收到的Ngap cause来设置的。ngap cause在38413里定

Cause #27 – missing or unknown DNN

原因#27 – 缺失或未知的DNN

The SMF includes this cause when DNN is not present in SmContextCreateData even though it is

required and not configured in SMF.

当SmContextCreateData中缺少DNN（尽管它是必需的）且未在SMF中配置时，SMF会包含此原因。

Cause #28 – unknown PDU session type

原因#28 – 未知的PDU会话类型

The SMF includes this cause when the PDU Session Establishment Request message includes a PDU

session type that is not supported by SMF.

当PDU会话建立请求消息包含SMF不支持的PDU会话类型时，SMF会包含此原因。

Cause #29 – user authentication or authorization failed

原因#29 – 用户认证或授权失败

The SMF includes this cause when DN authentication of the UE was performed and completed

unsuccessfully (Radius Authentication Timeout).

当对UE的DN认证执行并未成功完成（例如Radius认证超时）时，SMF会包含此原因。

Cause #32 – service option not supported

原因#32 – 服务选项不支持

The SMF supports this cause when the validation of received S-NSSAI fails against the allowed list of S-

NSSAI.

当接收到的S-NSSAI在验证时未通过允许的S-NSSAI列表时，SMF支持此原因。

Cause #33 – requested service option not subscribed

原因#33 – 请求的服务选项未订阅

The SMF supports this cause when the UE requests a service option for which it has no subscription.

当UE请求其未订阅的服务选项（也就是在UDM中的sm-data签约数据中没找到）时，SMF支持此原因。

Cause #38 – network failure

原因#38 – 网络故障

The SMF supports this cause when the requested service was rejected due to an error in the network.

This includes any internal failures or no response from any external NF during the PDN-setup

procedure.

当请求的服务因网络中的错误被拒绝时，SMF支持此原因。这包括任何内部故障或在PDN设置过程中未

收到任何外部NF的响应。

Cause #54 – PDU session does not exist

原因#54 – PDU会话不存在

The SMF supports this cause when it does not have any information about the PDU session which is

requested by the UE to transfer between 3GPP access and non-3GPP access or from the EPS to the

5GS.

当SMF没有关于UE请求在3GPP接入与非3GPP接入之间或从EPS到5GS之间传输的PDU会话的任何信息

时，SMF支持此原因。

Cause #70 – missing or unknown DNN in a slice

原因#70 – 切片中缺失或未知的DNN

The SMF supports this cause when the slice configuration is present but the requested DNN is not

configured under the slice in the SMF.

当切片配置存在但请求的DNN未在SMF中的切片下配置时，SMF支持此原因。

Cause #95 – Semantically incorrect message

原因#95 – 语义错误消息

This 5GSM cause reports receipt of a message with semantically incorrect content.

此5GSM原因报告接收到语义内容错误的消息。

For mandatory parameters (PDU Session Identity and Procedure Transaction Identity) with non-

semantical error also, the SMF sends this cause.

对于具有非语义错误的强制参数（PDU会话标识和过程事务标识），SMF也会发送此原因（Cause

#95）。