Name in the cause table
Missing or unknown DNN
Source: 3GPP TS 24.501 V20.1.0, clause 9.11.4.2, table 9.11.4.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
3GPP Scout / Reference / 5GSM causes / 5GSM causes #27 and #70
TS 24.5015GSM cause
5GSM causes #27 and #70: Missing or unknown DNN
Covers
TS 24.501 words these values in parallel, so they share this page. Each has its own section with the spec text and a plain explanation.
5GSM cause #27: Missing or unknown DNN
In plain words
The network sends this cause when the external DN rejects the requested service because a required DNN is missing or the DNN cannot be resolved.
Our summary of the spec text quoted below.
When it is used
This 5GSM cause is used by the network to indicate that the requested service was rejected by the external DN because the DNN was not included although required or if the DNN could not be resolved.
Source: 3GPP TS 24.501 V20.1.0, clause B.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
5GSM cause #70: Missing or unknown DNN in a slice
In plain words
The network sends this cause when external DN rejects service because a required DNN is missing or the DNN cannot be resolved in the slice.
Our summary of the spec text quoted below.
Name in the cause table
Missing or unknown DNN in a slice
Source: 3GPP TS 24.501 V20.1.0, clause 9.11.4.2, table 9.11.4.2.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
When it is used
This 5GSM cause is used by the network to indicate that the requested service was rejected by the external DN because the DNN was not included although required or if the DNN could not be resolved, in the slice.
Source: 3GPP TS 24.501 V20.1.0, clause B.1. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Same cause in EPS (TS 24.301)
TS 24.301 defines the corresponding cause for EPS. Its page quotes the EPS wording.
- ESM cause #27 (TS 24.301)
How this page was made
3GPP Scout built this page from TS 24.501 V20.1.0 as indexed on 2026-10-15. The quotes are copied from the spec, and code checks each one against the stored text and the 3GPP archive file before publishing. The plain-words lines were written by an AI model (GPT-6 Sol) and checked against the quotes by a second AI model from another company (Claude Opus 5.5). The official 3GPP text governs.