Protocol headers in a frame can be added or removed.
Features
The SmartNIC with Napatech Link-Inline™ Software supports
protocol encapsulation/decapsulation as follows.
- A maximum of 256 bytes of data can be defined to be added or removed from a frame.
- A maximum of 64000 bytes of data in total can be reserved in the SmartNIC.
- A maximum of 1024 encapsulation/decapsulation definitions can be reserved in the SmartNIC.
- Data to be added or removed must start with the MAC header up to the target header.
- FCS, inner/outer layer 3 and 4 checksums are recalculated after encapsulation and decapsulation.
The following protocol header fields are supported for encapsulation/decapsulation.
- MAC
- VLAN
- IPv4/IPv6
- UDP/TCP/SCTP/ICMP
- GTPv1-U
DPDK action types
The following DPDK action types are supported for protocol encapsulation/decapsulation.
- RTE_FLOW_ACTION_TYPE_RAW_ENCAP
- RTE_FLOW_ACTION_TYPE_RAW_DECAP
- RTE_FLOW_ACTION_TYPE_MODIFY_FIELD
GTP-U decapsulation and encapsulation
The SmartNIC can fully offload GTP-U encapsulation and decapsulation for UPF frame processing in the 5G core network architecture. This figure shows how the SmartNIC performs decapsulation of GTP-U protocol on uplink for the user plane.
As illustrated in the figure, the outer headers up to the GTP header are removed first, and the MAC header is added in the SmartNIC.
Note: In DPDK raw
decapsulation, if a VLAN header is included in a frame, it must be removed as well along
with other headers.
On downlink, the SmartNIC adds the outer headers up to the GTP header after removing the Ethernet header as shown in the following figure.