7.7.74 PDU Numbers

29.0603GPPGeneral Packet Radio Service (GPRS)GPRS Tunnelling Protocol (GTP) across the Gn and Gp interfaceRelease 17TS

The PDU Numbers information element contains the sequence number status corresponding to a PDP context in the old SGSN. This information element shall be sent only when acknowledged peer-to-peer LLC operation is used for the PDP context or when the "delivery order" QoS attribute is set in the PDP context QoS profile.

NSAPI identifies the PDP context for which the PDU Number IE is intended.

DL GTP-U Sequence Number is the number for the next downlink GTP-U T-PDU to be sent to the MS when "delivery order" is set.

UL GTP-U Sequence Number is the number for the next uplink GTP-U T-PDU to be tunnelled to the GGSN when "delivery order" is set.

The Send N-PDU Number is used only when acknowledged peer-to-peer LLC operation is used for the PDP context. Send N-PDU Number is the N-PDU number to be assigned by SNDCP to the next down link N-PDU received from the GGSN.

The Receive N-PDU Number is used only when acknowledged peer-to-peer LLC operation is used for the PDP context. The Receive N-PDU Number is the N-PDU number expected by SNDCP from the next up link N-PDU to be received from the MS.

The PDU Number IE will be repeated for each PDP Context for which this IE is required.

Bits

Octets

8

7

6

5

4

3

2

1

1

Type = 175 (Decimal)

2-3

Length = 9

4

Spare (0 0 0 0)

NSAPI

5-6

DL GTP-U Sequence Number

7-8

UL GTP-U Sequence Number

9-10

Send N-PDU Number

11-12

Receive N-PDU Number

Figure 7.7.74.1: PDU Numbers Information Element