ESM cause #33 Requested service option not subscribed
ESM cause (LTE NAS)3GPP TS 24.301 §9.9.4.4 and Annex B
What it means
Requested service option not subscribed: the subscriber isn't subscribed to this APN or service (e.g. IMS APN not in the profile).
Where you see it
In LTE NAS PDN connectivity reject, bearer resource reject or EPS bearer deactivation.
What to check
Check that the APN (e.g. 'ims') is in the subscriber's APN configuration in the HSS.
Check the GTPv2 Create Session Response and the HSS APN configuration for the same APN.
Got a trace with ESM cause #33 Requested service option not subscribed? Drop it in the analyzer: it finds the step that really failed first, which node sent the code and what to ask the other side. Captures, test-system PDFs and vendor exports. 5 free analyses a month, no sign-up.