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--- network_stuff:machine_learning:networking [2025/07/15 18:06] – jotasandoku
+++ network_stuff:machine_learning:networking [2025/07/15 21:08] (current) – jotasandoku
@@ Line 52: / Line 52: @@
 ==== LAN PROTOCOLS IN AI NETWORKING ====
-=== NVIDIA InfiniBand ===
+=== InfiniBand ===
 **InfiniBand** is a key technology for AI workloads, widely used in high-performance computing (HPC) and AI clusters for its **ultra-low latency**, **high throughput**, and **lossless performance**. It plays a crucial role in enabling efficient communication between nodes, especially for distributed machine learning tasks where large amounts of data need to be shared rapidly across many devices.
@@ Line 89: / Line 89: @@
   * **Interoperability**: Since RoCE is based on Ethernet, it can be more easily integrated with existing Ethernet-based infrastructure while still providing RDMA-like performance.
   * **Compatibility with AI Workloads**: Like InfiniBand, **RoCE** supports high-speed, low-latency, and lossless communication, making it ideal for distributed AI workloads such as training deep learning models across multiple GPUs or nodes.
-  * QP (Queue Pair): is a fundamental concept representing an RDMA connection. It consists of a send queue and a receive queue.
+  * __QP (Queue Pair)__: is a fundamental concept representing an RDMA connection. It consists of a send queue and a receive queue.
-  * BTH Base Transport Header: is a key component within RoCEv2 packets, carrying essential information like:#
+  * __BTH Base Transport Header__: is a key component within RoCEv2 packets, carrying essential information like:#
     * Packet Sequence Number (PSN), QP Number, and acknowledgment request bits.
 \\
-== ROCE VERBS ==
+Packet structure:
-**TODO**
+  Ethernet Header → IP Header → UDP Header → RoCE Packet (BTH + Payload)
+The Base Transport Header (BTH) is a key component of the InfiniBand transport layer. It contains essential information for delivering messages in InfiniBand or RDMA over Converged Ethernet (RoCE).
+\\
+Specifies the operation type (e.g., RDMA read, write, send, atomic).
+  * Solicited Event Indicator (SE): Indicates if a completion event is required.
+  * Migration State (M): Manages Queue Pair (QP) state transitions.
+  * P_Key: Identifies the partition the packet belongs to.
+  * Destination QP: Specifies the target Queue Pair for the message.
+  * Packet Sequence Number (PSN): Ensures ordered delivery and detects packet loss.
+  * Acknowledgment Request (A): Signals if an acknowledgment is needed for reliable transport.
+  * Resync Request (R): Handles retransmissions in reliable modes.
+== RDMA VERBS ==
+They are the **same** for both infiniband and rocev2
+  * ibv_alloc_pd: Allocates a Protection Domain for resources.
+  * ibv_reg_mr: Registers a memory region for RDMA operations.
+  * ibv_create_cq: Creates a Completion Queue to track work completions.
+  * ibv_create_qp: Creates a Queue Pair for sending and receiving data.
+  * ibv_modify_qp: Changes the state or properties of a Queue Pair.
+  * ibv_post_send: Posts a send work request to the send queue.
+  * ibv_post_recv: Posts a receive work request to the receive queue.
+  * ibv_poll_cq: Polls a Completion Queue for completed work requests.
+  * ibv_query_device: Retrieves attributes of an RDMA device.
+  * ibv_get_device_list: Lists available RDMA devices.

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