规范标准

Configuration Option配置选项

• The Configuration Option transports additional attributes of entries in the Service Discovery messages. Between 0 and n configuration items can be transported using the Configuration Option. These configuration items can include for example the name of the host or the Service.
  Configuration Option传输Service Discovery 报文中entries之外的其他属性。 可以使用配置选项传输0到n个配置项目。 这些配置项目可以包括,例如,主机或服务的名称。

• Receiving a config_item_string without an “=” sign shall be interpreted as key present without value.
  接收不带“=”符号的config_item_string应被解读为没有值的键
• Multiple config_item_string with the same key in a single configuration option shall be supported.
  应支持在单个配置选项中使用相同键的多个config_item_string
• If SdInstanceHostname exists, a key “hostname” with the value set to the string of this configuration item shall be added to the Configuration Option.
  如果SdInstanceHostname存在，则应在配置选项中添加一个键值为“主机名”的值，该值为该配置项的字符串
• Services exist, that are not identified by a unique 16 Bit Service ID but a unique value of the key otherserv. These services use the Service ID 0xFFFE and must always carry a configuration option with an otherserv record. ECUs receiving an entry with Service ID 0xFFFE shall use the configuration option and the otherserv record within in order to identify the relevant Service or Eventgroup configuration item. This means that two Service Instance with the same Service ID and Service Instance ID may exist as long as their otherserv record is different.
  有一些服务，它们不是由唯一的16位服务ID标识的，而是由键值otherserv的唯一值确定的。这些服务使用服务ID 0xFFFE，并且必须始终携带一个otherserv记录的configuration option。接收具有服务ID 0xFFFE的entry的ECU应使用configuration option以及含在其中的otherserv记录来识别相关的服务或事件组配置。这意味着具有相同服务ID和服务实例ID的两个服务实例可以存在，只要其他otherserv记录不同
• The configuration option shall be built based on configuration parameters mentioned in SWS_SD_00292.
  配置选项应根据SWS_SD_00292中提及的配置参数进行构建。

Options Array选项数组

The Option array is the last part of the Service Discovery Message The options in the options array carry additional information.
Option数组是服务发现消息的最后一部分。 选项数组中的选项带有附加信息。

• Reasons for sending a SubscribeEventgroupNegativeAcknowledgment include:
  发送SubscribeEventgroupNegativeAcknowledgement的原因包括：
  • Combination of Service ID, Instance ID, Eventgroup ID, and Major Version is unknown
    服务ID，实例ID，事件组ID和主要版本的组合未知
  • Required TCP-connection was not opened by client
    必需的TCP连接未由客户端打
  • Problems with the references options occurred (wrong values, missing endpoint, or conflicting endpoints)
    发生引用选项问题（错误值，缺少端点或冲突端点）
  • Resource problems at the Server .
    服务器的资源问题。
• If a SubscribeEventgroup entry referencing two conflicting Endpoint Options (UDP or TCP) is received then a SubscribeEventgroupNack shall be generated. Endpoint options are considered conflicting if they are of the same type but hold different values, like different IP or Port number.
  如果收到了引用两个冲突的Endpoint option（UDP或TCP）的SubscribeEventgroup entry，则会生成一个SubscribeEventgroupNack。如果Endpoint options属于相同类型但持有不同的值（如不同的IP或端口号），则认为endpoint option存在冲突。

• The SubscribeEventgroupNegativeAcknowledgment entry type shall be used to indicate that SubscribeEventgroup entry was NOT accepted. It shall be always sent instead of a SubscribeEventgroupAck if such an error occurred.
  SubscribeEventgroupNegativeAcknowledgement entry类型应用于表明SubscribeEventgroup entry不被接受。如果发生此类错误，它应始终被发送，而不是SubscribeEventgroupAck entry。
• Service ID, Instance ID, Major Version, Eventgroup ID, Counter, and Reserved shall be the same value as in the subscribe that is being answered.
  服务ID，实例ID，主要版本，事件组ID，计数器和保留的值应与正在应答的SubscribeEventgroup Entry中的值相同。
• The TTL shall be set to 0x000000.
  TTL应设置为0x000000。

StopSubscribeEventgroup entry

• StopSubscribeEventgroup entries shall set the entry fields exactly like the SubscribeEventgroup entry they are stopping, except the TTL field.
  StopSubscribeEventgroup条目应与其正在停止的SubscribeEventgroup entry的设置一样，TTL除外。

• The TTL shall be set to 0x000000.
  TTL应设置为0x000000。

• A Stop Subscribe Eventgroup Entry shall reference the same options the Subscribe Eventgroup Entry referenced. This includes but is not limited to Endpoint and Configuration options.
  Stop Subscribe Eventgroup Entry应引用其对应的Subscribe Eventgroup Entry相同的options 。 这包括但不限于Endpoint和Configuration option。

SubscribeEventgroupAck entry

• To acknowledge a SubscribeEventgroup entry, the SubscribeEventgroupAck entry shall be used and shall be used with the values as in the SubscribeEventgroup entry it answers.
  要确认SubscribeEventgroup entry，应使用SubscribeEventgroupAck entry，并应与其回复的SubscribeEventgroup entry中的值一致。

• Service ID, Instance ID, Major Version, Eventgroup ID, TTL, Counter, and Reserved shall be the same value as in the Subscribe that is being answered.
  服务ID，实例ID，主要版本，事件组ID，TTL，计数器和保留位应与正在应答的Subscribe中的值相同。

• A SubscribeEventgroupAck entry shall set the TTL field to the value of the SubscribeEventgroup entry, it acknowledges.
  SubscribeEventgroupAck entry应将TTL字段设置为它确认的SubscribeEventgroup entry的值。

• SubscribeEventgroupAck entries referencing events and notification events that are transported via multicast shall reference an IPv4 Multicast Option and/or and IPv6 Multicast Option. The Multicast Options state to which Multicast address and port the events and notification events will be sent to.
  针对通过multicast传输的events和notification events的SubscribeEventgroupAck entry应引用IPv4 Multicast Option和/或IPv6 Multicast Option 。Multicast Option表明notification event将会发送到哪个Multicast地址和port口。