...
PlantUml
| Expand | ||
|---|---|---|
| ||
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' |
Design
...
guidelines
- Each NetConf session should be terminated as soon as possible. Therefore any solution requiring a permanent NetConf session (e.g. for NetConf Notification) should be avoided.
(TODO: add here the reasons for such requirement/expectation. It may have something to do with avoiding TCP connection for better scale. However, for the required event streaming functionality, a permanent session is necessary. To be continued) - The NetConf client should be informed about the status of the VES connection. In the case of misconfigurationmissconfiguration, alarm events can not be sent to the MnS Consumer (alarm blindness). The only channel to troubleshoot such situation is via NetConf.
...
- Establish a NetConf session
A secure communication channel is required to establish a NetConf session. This can be done via Secure Shell (SSH) connection (RFC6242) or via Transport Layer Security (TLS) (RFC5539).
Due to the fact that O-RAN-Alliance requires TLS for HTTP traffic, it is preferred and recommended to use also TLS for NetConf. - Subscribe for VES events
Open: The details about the NetConf operation and the exact data structure are currently (2019-07-28) under discussion. The results of this discussion will be updated later here. - Inform VES client about a new subscription
An MnS Provider internal mechanism is necessary to verify the VES configuration. - Check VES connectivity
The verification of the VES communication channel id done by sending a VES heartbeat. - Response from VES server
Based on the response from the VES-HTTPS-Server (TCP/TLS/HTTP-POST/VES) the status attribute value of Managed Object instance (MOI) representing the subscription will be updated and exposed as attribute value change to all subscribers.- SUCCESS
Ths The HTTP response codes 20x indicate that the VES connection can be established and the subscription status attribute will be changed to the value of the HTTP-status (integer). - FAILED
The HTTP response codes different from 20x may require operator actions. Also, in this case, the subscription status attribute will be changed to the value of the HTTP-status (integer)
Open: is a textual status attribute useful? e.g. status: ok and status: "failed" or status: "failed (connection refused)" - Assumption; no - such translation is not subject of an OAM interface, it is subject of customer documentation and/or user interface (UI).
- SUCCESS
- Inform NetConf server about the status of the VES connection
The NetConf server must be triggered, to response the correct status back to the MnS Consumer. - NetConf response
The NetConf server sends a response including the VES connection status of the subscription.
Open: Shall the response also include all other attributes of the MOI representing the subscription? - Terminate NetConf session
Once the NetConf client received the NetConf response or the NetConf response timed out, the NetConf session should be actively terminated.
Note: All ODL based NetConf clients until release "Sodium" do not support such functionality yet - Also the ODL based implementation by ONAP CCSDK does not support such function.
It is currently (2019-07-28) under discussion, which of the involved open-source projects should implement such function - candidates are ODL, ONAP-CCSDK, ONAP-SDNC, ONAP-SDN-R, O-RAN-SC-NON-RT-RIC or O-RAN-SC-OAM. (TODO: add OAM Jira to track it). As a consequence, it is very likely that O-RAN-SC release A does not support the automated termination of the NetConf session after NetConf responses.
Figure
PlantUml
| Expand | ||
|---|---|---|
| ||
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' |
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Copyright 2019 highstreet technologies GmbH
' Licensed under the Apache License, Version 2.0 (the "License");
' you may not use this file except in compliance with the License.
' You may obtain a copy of the License at
'
' http://www.apache.org/licenses/LICENSE-2.0
'
' Unless required by applicable law or agreed to in writing, software
' distributed under the License is distributed on an "AS IS" BASIS,
' WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
' See the License for the specific language governing permissions and
' limitations under the License.
'
' Author: martin.skorupski@highstreet-technologies.com
@startuml
' Diagram
title
O-RAN-SC
O1-Interface: VES Subscription procedure
end title
box "\nManagement-Service (MnS) Provider\nManagedElement" #ED7D31
participant "<b>Client</b>" as vesc <<VES>>
participant "<b>Server</b>" as ncs <<NetConf>>
end box
box "\nManagement-Service (MnS) Consumer\nOAMController" #8064A2
participant "<b>Client</b>" as ncc <<NetConf>>
participant "<b>Server</b>" as vess <<VES>>
end box
autonumber "<b>[00]"
group VES Subscription
ncc <-> ncs: tcp/tls/netconf/830\nEstablish NetConf Session (hello, ...)
ncc -> ncs: subscribe for VES events
activate ncs
ncs -> vesc: inform about a new subscription
vesc -> vess: Check connectivity (e.g. tcp/tls/http/ves/heartbeat)
vesc <- vess: expected response "SUCCESS" (http status: 200)
vesc-> ncs: inform about status of the VES connection
ncs -> ncc: Response (expected: success, unexpected: failure)
deactivate ncs
ncc -> ncs: Terminate NetConf Session
end group
' End Diagram
' Format
header
<b><font color=#8888ff>License</font></b>
<b><font color=#8888ff>Apache 2.0</font></b>
end header
'caption "\n UML Formatting"
right footer
VES Subscription
Thanks to plantUml!
2019-07-27 | o-ran-sc.org
end footer
skinparam backgroundColor #fefefe
skinparam backgroundColor #fefefe
'skinparam handwritten true
skinparam roundcorner 15
skinparam databaseBorderColor #666666
skinparam databaseBackgroundColor #fefefe
skinparam databaseFontColor #666666
skinparam sequence {
MessageAlign left
ArrowColor #2277dd
ArrowFontColor #666666
ActorBorderColor #666666
LifeLineBorderColor #666666
LifeLineBackgroundColor #eeeeee
BoxFontColor #ffffff
BoxBorderColor #666666
GroupBorderColor #666666
GroupBackgroundColor #eeeeee
ParticipantBorderColor #666666
ParticipantBackgroundColor #ffffdd
'ParticipantFontName Impact
'ParticipantFontSize 17
ParticipantFontColor #666666
ActorBackgroundColor #ffffdd
'ActorFontColor DeepSkyBlue
'ActorFontSize 17
'ActorFontName Aapex
}
@enduml
...