The Release notes for RHOCP4.17[1] describe OpenShift SDN as follows:
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1.5.2.2. OpenShift SDN network plugin (Removed) 
OpenShift SDN network plugin was deprecated in 4.15 and 4.16. With this release, the SDN network plugin is no longer supported and the content has been removed from the documentation.
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However, we found many (46) words of "OpenShift SDN" or "SDN" in the Network document of RHOCP4.17[2].
As RHOCP 4.17 does not support OpenShift SDN, remove the unnecessary word "OpenShift SDN" or "SDN" from the RHOCP 4.17 documentation.[1] https://docs.redhat.com/en/documentation/openshift_container_platform/4.17/html-single/release_notes/index#ocp-4-17-web-console-patternfly_release-notes
[2] https://docs.redhat.com/en/documentation/openshift_container_platform/4.17/html/networking/index

    RHOCP 4.17

    1.
    2.
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    Note:
The RHOCP4.16 document describes the transition from SDN to OVN as follows.https://docs.redhat.com/en/documentation/openshift_container_platform/4.16/html-single/networking/index#migrate-from-openshift-sdn

24.5. Migrating from the OpenShift SDN network plugin 
> As a cluster administrator, you can migrate to the OVN-Kubernetes network plugin from the OpenShift SDN network plugin using the offline migration method or the limited live migration method.
> Warning
> It is not possible to upgrade a cluster to OpenShift Container Platform 4.17 if it is using the OpenShift SDN network plugin.
> You must migrate to the OVN-Kubernetes plugin before upgrading to OpenShift Container Platform 4.17.