8.2.3 F-TEID
29.2443GPPInterface between the Control Plane and the User Plane nodesRelease 17TS
The F-TEID IE type shall be encoded as shown in Figure 8.2.3-1. It indicates an F-TEID.
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Bits |
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Octets |
8 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
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1 to 2 |
Type = 21 (decimal) |
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3 to 4 |
Length = n |
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5 |
Spare |
CHID |
CH |
V6 |
V4 |
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6 to 9 |
TEID |
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m to (m+3) |
IPv4 address |
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p to (p+15) |
IPv6 address |
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q |
CHOOSE ID |
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k to (n+4) |
These octet(s) is/are present only if explicitly specified |
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Figure 8.2.3-1: F-TEID
The following flags are coded within Octet 5:
– Bit 1 – V4: If this bit is set to "1" and the CH bit is not set, then the IPv4 address field shall be present, otherwise the IPv4 address field shall not be present.
– Bit 2 – V6: If this bit is set to "1" and the CH bit is not set, then the IPv6 address field shall be present, otherwise the IPv6 address field shall not be present.
– Bit 3 – CH (CHOOSE): If this bit is set to "1", then the TEID, IPv4 address and IPv6 address fields shall not be present and the UP function shall assign an F-TEID with an IP4 or an IPv6 address if the V4 or V6 bit is set respectively. This bit shall only be set by the CP function.
– Bit 4 – CHID (CHOOSE ID): If this bit is set to "1", then the UP function shall assign the same F-TEID to the PDRs requested to be created in a PFCP Session Establishment Request or PFCP Session Modification Request with the same CHOOSE ID value. This bit may only be set to "1" if the CH bit it set to "1". This bit shall only be set by the CP function.
– Bit 5 to 8: Spare, for future use and set to "0".
At least one of the V4 and V6 flags shall be set to "1", and both may be set to "1" for both scenarios:
– when the CP function is providing F-TEID, i.e. both IPv4 address field and IPv6 address field may be present; or
– when the UP function is requested to allocate the F-TEID, i.e. when CHOOSE bit is set to "1", and the IPv4 address and IPv6 address fields are not present.
Octet 6 to 9 (TEID) shall be present and shall contain a GTP-U TEID, if the CH bit in octet 5 is not set. When the TEID is present, if both IPv4 and IPv6 addresses are present in the F-TEID IE, then the TEID value shall be shared by both addresses.
Octets "m to (m+3)" and/or "p to (p+15)" (IPv4 address / IPv6 address fields), if present, it shall contain the respective IP address values.
Octet q shall be present and shall contain a binary integer value if the CHID bit in octet 5 is set to "1".