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Clarification on the packet length needed to configure VFs

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As per CUS spec, the MTU can be 1500 or 9000 B, where MTU = IQ data format.

Packet length = ethernet header + RTE_PKTMBUF_HEADROOM + MTU

However, xran assumes different definitions of the MTU:
(1) in xran_init_mbuf_pool(): MTU = ethernet header + IQ data format;
(2) in xran_get_num_prb_elm(), xran_init_PrbMap_from_cfg(), xran_init_PrbMap_from_cfg_for_rx(), xran_init_PrbMap_by_symbol_from_cfg(): MTU = complitely wrong (as the IQ data format is not well included).

Additionally, xran assumes that the max MTU 9600 B, instead of 9000 B as per spec.
Nevertheless, I left 9600 B in all config files and docs due to wrong calculation of (2) for the total number of PRBs per fragment.
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Teodora
2025-05-13 12:55:18 +02:00
parent 29acc08f9e
commit e6e9aaed7f
1 changed files with 1 additions and 1 deletions
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doc/ORAN_FHI7.2_Tutorial.md
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@@ -745,7 +745,7 @@ In the following, we will use these short hands:
- `IF_NAME`: Physical network interface through which you can access the RU
- `VLAN`: the VLAN tag as recommended by the RU vendor
- `MTU`: the MTU as specified by the RU vendor, and supported by the NIC
- `MTU`: this MTU must be higher than supported by the RU vendor due to additional ethernet header of 14 B and DPDK packet header `RTE_PKTMBUF_HEADROOM` of 128 B
- `DU_U_PLANE_MAC_ADD`: DU U plane MAC address
- `U_PLANE_PCI_BUS_ADD`: PCI bus address of the VF for U plane
- `DU_C_PLANE_MAC_ADD`: DU C plane MAC address