Tech-invite3GPPspecsSIPRFCs
Overview21222324252627282931323334353637384‑5x

Content for  TS 29.500  Word version:  16.4.0

Top   Top   Up   Prev   Next
1…   5…   5.2.3   5.2.4…   6…   6.4…   6.5…   6.6…   6.7…   6.10…   6.11…   A…

 

6.11  Detection and handling of late arriving requests |R16|Word‑p. 70
6.11.1  General
The procedures specified in this clause aim at handling more efficiently requests which may arrive late at upstreams entities, e.g. in networks experiencing processing or transport delays.
These procedures are optional to support. When supported, the use of these procedures is dependent on operator policy.
6.11.2  Detection and handling of requests which have timed out at the HTTP client
6.11.2.1  General
This procedure enables an HTTP server which receives a request to know when the request times out at the HTTP client, and to stop further processing, at the receiver and further upstream NFs, a request which has timed out at the HTTP client.
The HTTP client and HTTP server shall be NTP synchronized. This procedure may be used between NFs pertaining to the same PLMN, and if allowed by operator policy, between NFs pertaining to different PLMNs.
6.11.2.2  Principles
An HTTP client originating a request may include in the request the 3gpp-Sbi-Sender-Timestamp and the 3gpp-Sbi-Max-Rsp-Time headers indicating respectively the absolute time at which the request is originated and the maximum time period to complete the processing of the request; both headers together indicate the absolute time at which the request times out at the HTTP client.
Upon receipt of a request which contains the 3gpp-Sbi-Sender-Timestamp and the 3gpp-Sbi-Max-Rsp-Time headers, the HTTP server should check that the request has not already timed out at the originating HTTP client. The HTTP server may perform additional similar checks during the processing of the request, e.g. upon receipt of a response from the next upstream NF service.
Based on local configuration, the HTTP server may reject a request that is known to have timed out with the HTTP status code "504 Gateway Timeout" and the protocol error "TIMED_OUT_REQUEST"; it may alternatively drop the request. If so, the HTTP server should initiate the release of any resource it may have successfully created towards an upstream entity, to avoid hanging resources in the network.
Up
6.12  Binding between an NF Service Consumer and an NF Service Resource |R16|
6.12.1  General
A Binding Indication for an NF Service Resource may be provided to an NF Service Consumer of the resource as part of the Direct or Indirect Communication procedures, to be used in subsequent related service requests. This allows the NF Service Resource owner to indicate that the NF Service Consumer, for a particular resource, should be bound to an NF service instance, NF instance, NF service set or NF set. See clause 6.3.1.0 of TS 23.501 and clause 4.17.12 of TS 23.502.
A binding may be established or updated as part of a:
  1. service response creating or modifying a resource, to be used for subsequent requests targeting this resource (see clause 4.17.12.2 of TS 23.502), for any API that defines resources;
  2. service request, if the NF Service Consumer can also act as an NF Service Producer for later communication from the contacted NF Service Producer, to be used for subsequent service requests initiated by the contacted NF Service Producer (see clause 4.17.12.3 of TS 23.502);
  3. service request creating or modifying an explicit or an implicit subscription, or as part of a notification response, to be used for subsequent notification requests initiated by the NF Service Producer (see clause 4.17.12.3 of TS 23.502);
  4. service response creating an implicit or explicit subscription or updating a subscription, or as part of a notification request, to be used for subsequent operations on the subscription (see clause 4.17.12.4 of TS 23.502);
  5. service request creating a callback (other than notification) resource (e.g. V-SMF or I-SMF callback URI sent to the H-SMF or SMF), or as part of a callback response, to be used for subsequent callback requests initiated by the NF Service Producer (e.g. H-SMF or SMF initiated PDU session modification).
Two types of binding information are defined to manage the binding between an NF Service Consumer and an NF Service Resource:
  1. A Binding Indication conveys binding information for a resource which must be stored by the consumer (client) of that resource and used by the client to direct future requests to the resource. When contained in a service request, the binding information is associated with a resource owned by the NF Service Consumer for the current transaction. When contained in a service response, the binding information is associated with a resource owned by the NF Service Producer for the current transaction.
  2. A Routing Binding Indication conveys binding information to direct a request from a client to a server which has the resource context. A Routing Binding Indication shall only be contained in a service request.
A same service request may convey more than one Binding Indication, e.g.:
  • to provide bindings for notification or callback (i.e. bullets 3 or 5) and for other services that the NF service consumer can provide later as a NF Service Producer (i.e. bullet 2); or
  • to provide binding information for different event notifications, when creating a subscription on behalf of another NF (see clause 6.12.4).
The scope parameter in a Binding Indication in a service request identifies the applicability of (i.e. scenario associated with) the binding information.
A service request may convey one or more Binding Indications as described above using a 3gpp-Sbi-Binding header and/or include a Binding Routing Indication to influence routing of the request e.g. to an appropriate set of NF Service Producers or to an appropriate service set of the NF Service Producer using a 3gpp-Sbi-Routing-Binding header. A service response may convey a Binding Indication for a resource using a 3gpp-Sbi-Binding header.
If an SCP receives a Routing Binding Indication within a service or notification request and decides to forward that request to a next-hop SCP, it shall include the Routing Binding Indication in the forwarded request.
Binding Indications and Routing Binding Indications shall include the Binding level and one or more Binding entity IDs representing all NF service instances that are capable to serve service requests targeting the resource, i.e. that share the same resource contexts.
The Binding Level indicates a preferred binding to either a NF Instance, a NF set, a NF Service Instance or a NF Service Set. When sending a request targeting the resource, the binding entity corresponding to the binding level shall be selected whenever possible. If this is not possible, e.g. because the preferred binding entity is not reachable, the request should be sent to any other Binding entity signalled in the Binding Indication or Routing Binding Indication, in the following decreasing order of priority:
  • select an NF service instance in the same NF service set, if a NF service Set ID was signalled in the Binding Indication or Routing Binding Indication;
  • select an equivalent NF service instance in the same NF instance, if an NF instance ID was signalled in the Binding Indication or Routing Binding Indication;
  • select an NF service instance in an equivalent NF service set of another NF instance of the NF set, if an NF Service Set ID and an NF Set ID were signalled in the Binding Indication or Routing Binding Indication;
  • select an equivalent NF service instance in another NF instance of the NF Set, if an NF Set ID was signalled in the Binding Indication or Routing Binding Indication.
Binding Indications shall not be used if a particular resource can only be served by a specific NF service instance of an NF instance, i.e. if NF service instances of a same NF service are not capable to share resource inside the NF Instance. A resource for which no Binding Indication or Routing Binding Indication is signalled shall be considered to be bound exclusively to one NF service instance, unless the NF Service resource owner instance is part of an NF set (or AMF set) or an NF service set, or unless its NF profile in the NRF indicates that its supports NF service persistence within the NF instance (see clause 6.5 of TS 23.527).
Up
6.12.2  Binding created as part of a service responseWord‑p. 72
An NF Service Producer may provide a Binding Indication in a service response by including a 3gpp-Sbi-Binding header (see clause 5.2.3.2.5) in the HTTP response with:
  • the binding level (bl) parameter indicating a preferred binding to either a NF Service Instance, a NF Service Set, a NF Instance or a NF set;
  • at least one of the NF Service Instance (nfservinst), NF Service Set (nfservset), NF instance (nfinst) and NF Set (nfset) parameters, set to a NF Service Instance ID, NF Service Set ID, NF Instance ID and NF Set ID respectively, as described in Table 6.3.1.0-1 of TS 23.501.
The NF Service Consumer shall store the Binding Indication received from the NF Service Producer and include it in a 3gpp-Sbi-Routing-Binding header in subsequent related service requests targeting the NF Service Resource. The NF Service Consumer or the SCP shall use this information for selecting or reselecting an NF Service Producer which has access to the NF Service Resource context, for direct or indirect communication respectively, as specified in clause 6.3.1.0 of TS 23.501.
Up
6.12.3  Binding created as part of a service request
An NF Service Consumer may provide a Binding Indication in a service request by including a 3gpp-Sbi- Binding header (see clause 5.2.3.2.6) in an HTTP request with:
  • the binding level (bl) parameter indicating a preferred binding to either a NF Service Instance, a NF Service Set, a NF Instance or a NF set;
  • at least one of the NF Service Instance (nfservinst), NF Service Set (nfservset), NF instance (nfinst) and NF Set (nfset) parameters, set to a NF Service Instance ID, NF Service Set ID, NF Instance ID and NF Set ID respectively, as described in Table 6.3.1.0-1 of TS 23.501;
  • the scope parameter indicating "other-service";
  • optionally the service name parameter indicating the service(s) for which the binding information applies. If no service name is indicated in the Binding Indication, the binding information applies to any service that the NF Service Consumer can provide as an NF Service Producer.
The NF Service Producer shall store the Binding Indication received from the NF Service Consumer and include it in a 3gpp-Sbi-Routing-Binding header in subsequent service requests it sends, where the NF Service Consumer acts as an NF Service Producer. The NF Service Producer (when acting as a NF service consumer) or the SCP shall use this information for selecting or reselecting an NF Service Producer which has access to the original consumer's NF Service Resource context, for direct or indirect communication respectively, as specified in clause 6.3.1.0 of TS 23.501.
Up
6.12.4  Binding for explicit or implicit subscription requestsWord‑p. 73
A NF Service Consumer may provide a Binding Indication in a service request creating an explicit or an implicit subscription by including a 3gpp-Sbi-Binding header (see clause 5.2.3.2.6) in an HTTP request with:
  • the binding level (bl) parameter indicating a preferred binding to either a NF Service Instance, a NF Service Set, a NF Instance or a NF set;
  • at least one of the NF Service Instance (nfservinst), NF Service Set (nfservset), NF instance (nfinst) and NF Set (nfset) parameters, set to a NF Service Instance ID, NF Service Set ID, NF Instance ID and NF Set ID respectively, as described in Table 6.3.1.0-1 of TS 23.501;
  • the scope parameter indicating "subscription-events" if the binding information is applicable to subscription change event notification (see clause 4.17.12.4 of TS 23.502);
  • optionally, the scope parameter indicating "callback" if the binding information is applicable to notification and callback requests; the absence of this parameter shall also be interpreted as binding information is applicable to callback (i.e. notification) requests;
  • optionally the service name parameter indicating the service that will handle the notification.
When binding information is applicable to notification/callback requests, corresponding notifications are bound to:
  • the NF instance or NF set (according to the binding level), if no service name was received;
  • the specific service (indicated by the service name parameter) of the NF instance or NF set (according to the binding level), if a service name was received; or
  • the NF service instance or NF service set (according to the binding level).
The NF Service Producer shall store the Binding Indication received from the NF Service Consumer and include it in a 3gpp-Sbi-Routing-Binding header in subsequent notification requests it sends to the NF Service Consumer (that acts as an HTTP server) related to this subscription. The NF Service Producer or the SCP shall use this information for selecting or reselecting an NF Service Consumer (HTTP server) which has access to the original consumer's NF Service Resource context, for direct or indirect communication respectively, as specified in clause 6.3.1.0 of TS 23.501. If the notification endpoint provided in the subscription is not reachable, the NF Service Producer or SCP shall look up for an alternative notification endpoint address at the service level (i.e. NF Service registered in NRF) if the Binding Indication contains a service name or a binding to an NF Service Instance or NF Service Set, or at the NF instance level (i.e. NF Profile registered in NRF) otherwise. The NF Service Producer or SCP shall exchange the authority part of the notification URI (or callback URI) with the new notification endpoint address and shall use that URI in subsequent notifications.
The NF Service Consumer may provide an updated Binding Indication to the NF Service Producer in a service request modifying the subscription or in a notification response.
The NF Service Producer may also provide a Binding Indication in a service response creating or modifying an explicit or an implicit subscription by including a 3gpp-Sbi-Binding header (see clause 5.2.3.2.5) in the HTTP response as specified in clause 6.12.2. If the service request creates a resource and a subscription, the Binding Indication returned in the HTTP response shall apply to both the NF Service Resource and the subscription, i.e. the created resource and subscription shall be bound to the same (service) set of producers or producer instance. The NF Service Consumer shall store the Binding Indication received from the NF Service Producer and include it in a 3gpp-Sbi-Routing-Binding header in subsequent related service requests as specified in clause 6.12.2.
A subscription request may also contain a Routing Binding Indication that can be used in case of indirect communication by the SCP to route the message to the NF Service Producer.
A service request creating an explicit subscription on behalf of another NF (e.g. UDM subscribing to an AMF event on behalf of the NEF) may include a Binding Indication for subscription change event notification (e.g. notifications to UDM upon AMF change) and a Binding Indication for the event notifications to the other NF (e.g. AMF notification to the NEF). The scope parameter shall be set to "subscription-events" in the former Binding Indication and it shall be set to "callback" or be absent in the latter Binding Indication.
Up
6.12.5  Binding for service requests creating a callback resourceWord‑p. 74
A NF Service Consumer may provide a Binding Indication in a service request creating a callback (other than notification) resource (e.g. V-SMF or I-SMF callback URI sent to the H-SMF or SMF), by including a 3gpp-Sbi-Binding header (see clause 5.2.3.2.6) in an HTTP request as specified in clause 6.12.4, with the scope parameter being absent or indicating "callback".
The NF Service Producer shall behave as specified in clause 6.12.4, with the "notification endpoint" being replaced by the callback endpoint.
The NF Service Consumer may provide an updated Binding Indication as part of a callback response, to be used for subsequent callback requests initiated by the NF Service Producer.
Up

Up   Top   ToC