3GPP Scout / Reference / 5GS NAS timers / Timers T3590, T3591, T3592 and T3594
TS 24.501NAS timer
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.
In plain words
The SMF starts T3590 when transmitting a PDU SESSION AUTHENTICATION COMMAND message and retransmits it when the timer expires.
Our summary of the spec text quoted below.
15s In WB-N1/CE mode, 23s For access via a satellite NG-RAN cell, 21s NOTE 5
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Transmission of PDU SESSION AUTHENTICATION COMMAND message
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Retransmission of PDU SESSION AUTHENTICATION COMMAND message
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
PDU SESSION AUTHENTICATION COMPLETE message received
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
PROCEDURE TRANSACTION PENDING
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
In plain words
The SMF starts T3591 when transmitting a PDU SESSION MODIFICATION COMMAND message and retransmits it when the timer expires.
Our summary of the spec text quoted below.
16s In WB-N1/CE mode, 24s For access via a satellite NG-RAN cell, 22s NOTE 5
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Transmission of PDU SESSION MODIFICATION COMMAND message
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Retransmission of PDU SESSION MODIFICATION COMMAND message
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
PDU SESSION MODIFICATION COMPLETE message received or PDU SESSION MODIFICATION [...]
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
In plain words
The SMF starts T3592 when transmitting a PDU SESSION RELEASE COMMAND message and retransmits it when the timer expires.
Our summary of the spec text quoted below.
16s In WB-N1/CE mode, 24s For access via a satellite NG-RAN cell, 22s NOTE 5
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Transmission of PDU SESSION RELEASE COMMAND message
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Retransmission of PDU SESSION RELEASE COMMAND message
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
PDU SESSION RELEASE COMPLETE message received or N1 SM [...]
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
In plain words
The SMF starts T3594 when transmitting a SERVICE-LEVEL AUTHENTICATION COMMAND message and retransmits it when the timer expires.
Our summary of the spec text quoted below.
15s In WB-N1/CE mode, 23s For access via a satellite NG-RAN cell, 21s NOTE 5
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Transmission of SERVICE-LEVEL AUTHENTICATION COMMAND message
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
Retransmission of SERVICE-LEVEL AUTHENTICATION COMMAND message
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
SERVICE-LEVEL AUTHENTICATION COMPLETE message received
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
PROCEDURE TRANSACTION PENDING
Source: 3GPP TS 24.501 V20.1.0, clause 10.3, table 10.3.2. © 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC). Official text: 24501-k10.zip in the 3GPP archive.
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.