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update network stack documentation;

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pull/121/merge
Bryan Biedenkapp 3 weeks ago
parent 9a31910526
commit f7023e2965
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docs/TN.1000 - Network Stack Technical Documentation.md
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@ -1177,25 +1177,21 @@ The DMR network packet uses the TAG_DMR_DATA identifier (`0x444D5244` or ASCII "
Complete Packet (87 bytes): Complete Packet (87 bytes):
90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 00 12 34 56 78 00 00 4E 20 00 23 00 00 00 00 00 00 | 44 4D 52 44 05 00 00 AA BB 00 CC DD 00 00 00 01 02 00 00 00 00 [33 bytes DMR data...] 00 7F 90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 00 12 34 56 78 00 00 4E 20 00 23 00 00 00 00 00 00 | 44 4D 52 44 05 00 00 AA BB 00 CC DD 00 00 00 01 02 00 00 00 00 [33 bytes DMR data...] 00 7F
├─────────── RTP (12) ───────────┤ ├──────────────────────── FNE (20) ────────────────────────┤ ├────────────────────────────────── DMR (55) ────────────────────────────────┤ ├─────────── RTP (12) ───────────┤ ├──────────────────────── FNE (20) ────────────────────────┤ ├────────────────────────────────── DMR (55) ─────────────────────────────────────────────────┤
DMR Payload breakdown: DMR Payload breakdown:
44 4D 52 44 05 00 00 AA BB 00 CC DD 00 00 00 01 02 00 00 00 00 [33 bytes DMR frame...] 00 7F 44 4D 52 44 05 00 AA BB 00 CC DD 00 00 00 01 02 00 00 00 00 [33 bytes DMR frame...] 00 7F
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ └─[Reserved 4]──┤ │ │ │ │ │ │ │ │ │ │ │ │ └───────┴ Reserved │ │
│ │ │ │ │ │ │ │ │ │ └─ Slot/FLCO/DataType: 0x02 │ │ │ │ │ │ │ │ │ │ └─────────── Slot/FLCO/DataType: 0x02 │ │
│ │ │ │ │ │ │ │ │ └──── Control: 0x01 │ │ │ │ │ │ │ │ │ └────────────── Control: 0x01 │ │
│ │ │ │ │ │ │ └─[Reserved 3] │ │ │ │ │ │ │ └─────┴───────────────── Reserved │ │
│ │ │ │ │ └─[DestID 3rd byte]──── Dest ID: 0x00CCDD (52445) │ │ │ │ │ └─────┴─────────────────────────── Dest ID: 0x00CCDD (52445)│ │
│ │ │ │ └─[DestID 2nd byte] │ │ │ └─────┴──────────────────────────────────── Src ID: 0x00AABB (43707) │ │
│ │ │ └─[DestID 1st byte] │ │ └───────────────────────────────────────────── Sequence: 5 │ │
│ │ └─[SrcID 3rd byte]────────────────── Src ID: 0x0000AABB (43707) └────────┴──────────────────────────────────────────────── Tag: "DMRD" (0x444D5244) │ │
│ └─[SrcID 2nd byte] └─── BER: 0x00
│ └─[SrcID 1st byte] └─ RSSI: 0x7F (127)
│ └─────────────────────────────────────── Sequence: 5
└──────────────────────────────────────────────── Tag: "DMRD" (0x444D5244)
└─ (DMR frame at offset 20)──────────────── BER: 0x00
└─ RSSI: 0x7F (127)
``` ```
#### P25 Message Formats #### P25 Message Formats
@ -1221,6 +1217,61 @@ bool BaseNetwork::writeP25LDU1(const p25::lc::LC& control,
} }
``` ```
**P25 Message Header Structure (24 bytes):**
**Control Byte (`CONTROL_BYTE`) Flags:**
The Control Byte at offset 14 is a bitmask defined by `enum CONTROL_BYTE` in `BaseNetwork.h`. It is passed as the `controlByte` parameter to `writeP25TDU()` and stored in the TDU packet to signal in-band network control to the receiving endpoint. Multiple flags may be OR'd together. A value of `0x00` means no control operation is requested.
| Bit Mask | Name | Description |
|----------|------|-------------|
| `0x80` | `NET_CTRL_GRANT_DEMAND` | Grant demand — peer is requesting a channel grant for an ongoing call |
| `0x40` | `NET_CTRL_GRANT_DENIAL` | Grant denial — FNE is denying a channel grant request |
| `0x20` | `NET_CTRL_SWITCH_OVER` | Call source RID switch over — the originating radio ID changed mid-call |
| `0x08` | `NET_CTRL_GRANT_ENCRYPT` | Encrypted grant — the associated channel grant is for an encrypted call |
| `0x01` | `NET_CTRL_U2U` | Unit-to-unit — this is a unit-to-unit (private) call, not a group call |
**P25 Message Header Structure (24 bytes):**
The message header created by `createP25_MessageHdr()` contains:
| Offset | Length | Field | Description |
|--------|--------|-------|-------------|
| 0-3 | 4 | P25 Tag | "P25D" (0x50323544) |
| 4 | 1 | LCO | Link Control Opcode |
| 5-7 | 3 | Source ID | Calling radio ID |
| 8-10 | 3 | Destination ID | Target talkgroup/radio |
| 11-12 | 2 | System ID | Site system ID |
| 13 | 1 | Reserved | Reserved (0x00) |
| 14 | 1 | Control Byte | Network control flags (`CONTROL_BYTE` bitmask) |
| 15 | 1 | MFId | Manufacturer ID |
| 16-18 | 3 | Network ID | FNE network/WACN ID |
| 19 | 1 | Slot / Reserved | Bit 7: slot number; bits 4–0: P2 DUID (if Phase 2, else 0x00) |
| 20 | 1 | LSD1 | Low Speed Data byte 1 |
| 21 | 1 | LSD2 | Low Speed Data byte 2 |
| 22 | 1 | DUID | Data Unit ID (0x05 LDU1, 0x0A LDU2, 0x03 TDU, 0x07 TSDU, 0x0F TDULC) |
| 23 | 1 | Frame Length | Payload data length in bytes (0x00 for LDU1/LDU2; set for TDU/TSDU/TDULC) |
```
P25 Message Header (first 24 bytes):
50 32 35 44 00 00 AA BB 00 CC DD 00 01 00 00 00 00 00 01 00 00 00 05 00
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └─────── Frame Length: 0x00
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └────────── DUID: 0x05 (LDU1)
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └───────────── LSD2: 0x00
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └──────────────── LSD1: 0x00
│ │ │ │ │ │ │ │ │ │ │ │ │ │ └─────────────────── Slot/Reserved: 0x00
│ │ │ │ │ │ │ │ │ │ │ │ └─────┴────────────────────── Net ID: 0x000001 (1)
│ │ │ │ │ │ │ │ │ │ │ └─────────────────────────────── MFId: 0x00 (Standard)
│ │ │ │ │ │ │ │ │ │ └────────────────────────────────── Control Byte: 0x00
│ │ │ │ │ │ │ │ │ └───────────────────────────────────── Reserved: 0x00
│ │ │ │ │ │ │ └──┴──────────────────────────────────────── Sys ID: 0x0001 (1)
│ │ │ │ │ └─────┴────────────────────────────────────────────── Dst ID: 0x00CCDD (52445)
│ │ │ └─────┴─────────────────────────────────────────────────────── Src ID: 0x0000AABB (43707)
│ │ └──────────────────────────────────────────────────────────────── LCO: 0x00 (Group Voice)
└────────┴─────────────────────────────────────────────────────────────────── Tag: "P25D" (0x50323544)
```
**P25 LDU1 Packet Structure:** **P25 LDU1 Packet Structure:**
The P25 LDU1 message uses DFSI encoding to pack 9 IMBE voice frames with link control data. The total size is 193 bytes (`P25_LDU1_PACKET_LENGTH = 193U`), which includes: The P25 LDU1 message uses DFSI encoding to pack 9 IMBE voice frames with link control data. The total size is 193 bytes (`P25_LDU1_PACKET_LENGTH = 193U`), which includes:
@ -1245,25 +1296,6 @@ The P25 LDU1 message uses DFSI encoding to pack 9 IMBE voice frames with link co
**Total P25 LDU1 Size:** 193 bytes (`P25_LDU1_PACKET_LENGTH`) **Total P25 LDU1 Size:** 193 bytes (`P25_LDU1_PACKET_LENGTH`)
**P25 Message Header Structure (24 bytes):**
The message header created by `createP25_MessageHdr()` contains:
| Offset | Length | Field | Description |
|--------|--------|-------|-------------|
| 0 | 4 | P25 Tag | "P25D" (0x50323544) |
| 4 | 1 | DUID | Data Unit ID (e.g., 0x05 for LDU1, 0x0A for LDU2) |
| 5 | 1 | Control Byte | Network control flags |
| 6 | 1 | LCO | Link Control Opcode |
| 7 | 1 | MFId | Manufacturer ID |
| 8-10 | 3 | Source ID | Calling radio ID |
| 11-13 | 3 | Destination ID | Target (talkgroup/radio) |
| 14-16 | 3 | Reserved | Reserved bytes |
| 17 | 1 | RSSI | Signal strength |
| 18 | 1 | BER | Bit error rate |
| 19-22 | 4 | Reserved | Reserved bytes |
| 23 | 1 | Count | Total payload size |
**DFSI Encoding Details:** **DFSI Encoding Details:**
The Digital Fixed Station Interface (DFSI) encoding is a TIA-102.BAHA standard for transporting P25 voice over IP. Each IMBE voice frame (11 bytes of raw IMBE data) is encoded using the `p25::dfsi::LC::encodeLDU1()` method with a specific frame type: The Digital Fixed Station Interface (DFSI) encoding is a TIA-102.BAHA standard for transporting P25 voice over IP. Each IMBE voice frame (11 bytes of raw IMBE data) is encoded using the `p25::dfsi::LC::encodeLDU1()` method with a specific frame type:
@ -1285,21 +1317,7 @@ The DFSI frames embed the Link Control (LC) and Low Speed Data (LSD) information
``` ```
[RTP: 12 bytes] [FNE: 20 bytes] [P25 LDU1 Payload: 193 bytes] [RTP: 12 bytes] [FNE: 20 bytes] [P25 LDU1 Payload: 193 bytes]
P25 Message Header (first 24 bytes): [P25 Message Header 24 bytes]
50 32 35 44 05 00 03 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 A9
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ └─ Count: 0xA9 (169)
│ │ │ │ │ │ │ │ │ │ │ │ │ └──┴──┴──┴──── Reserved
│ │ │ │ │ │ │ │ │ │ │ │ └────────────────── BER: 0x00
│ │ │ │ │ │ │ │ │ │ │ └───────────────────── RSSI: 0x7F (127)
│ │ │ │ │ │ │ │ │ └──┴──┴────────────────────── Reserved
│ │ │ │ │ │ │ └──┴───────────────────────────────────── Dest ID: 0x00CCDDEE (13492718)
│ │ │ │ │ │ └───────────────────────────────────────────────── Src ID: 0x0000AABB (43707)
│ │ │ │ │ └──────────────────────────────────────────────────── MFId: 0x90 (Standard)
│ │ │ │ └─────────────────────────────────────────────────────── LCO: 0x03 (Group Voice Channel User)
│ │ │ └────────────────────────────────────────────────────────── Control: 0x00
│ │ └───────────────────────────────────────────────────────────── DUID: 0x05 (LDU1)
└────────┴──────────────────────────────────────────────────────────────── Tag: "P25D" (0x50323544)
DFSI Voice Frames (offsets 24-177): DFSI Voice Frames (offsets 24-177):
Offset 24: [22 bytes] LDU1_VOICE1 (DFSI frame type 0x62) Offset 24: [22 bytes] LDU1_VOICE1 (DFSI frame type 0x62)
@ -1323,7 +1341,7 @@ Additional Data (offsets 178-192):
- `MSG_HDR_SIZE = 24U` - `MSG_HDR_SIZE = 24U`
- Total allocated size: 193 + 8 = 201 bytes - Total allocated size: 193 + 8 = 201 bytes
**LDU2 (Link Data Unit 2) with DFSI Encoding:** **P25 LDU2 Packet Structure:**
LDU2 has a similar structure to LDU1 but uses different DFSI frame types and contains Encryption Sync (ESS) data instead of Link Control in frames 3-8. Total size is 181 bytes (`P25_LDU2_PACKET_LENGTH = 181U`). LDU2 has a similar structure to LDU1 but uses different DFSI frame types and contains Encryption Sync (ESS) data instead of Link Control in frames 3-8. Total size is 181 bytes (`P25_LDU2_PACKET_LENGTH = 181U`).
@ -1358,56 +1376,23 @@ The TDU packet consists of:
**Total TDU Payload Size (after FNE):** 24 bytes (`MSG_HDR_SIZE = 24U`) **Total TDU Payload Size (after FNE):** 24 bytes (`MSG_HDR_SIZE = 24U`)
**Raw TDU Packet Example (hexadecimal):**
```
[RTP: 12 bytes] [FNE: 20 bytes] [P25 TSDU: 24 bytes]
Complete Packet (101 bytes):
90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 01 12 34 56 78 00 00 4E 20 00 45 00 00 00 00 00 00 | 50 32 35 44 07 00 00 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 2D
├─────────── RTP (12) ────────────┤ ├────────────────────── FNE (20) ─────────────────────────┤ ├───────────────────────────────── P25 TSDU (24) ────────────────────────┤
```
**Constants:** **Constants:**
- `MSG_HDR_SIZE = 24U` (defined in `BaseNetwork.h`) - `MSG_HDR_SIZE = 24U` (defined in `BaseNetwork.h`)
- `PACKET_PAD = 8U` - `PACKET_PAD = 8U`
- Total allocated size: 24 + 8 = 32 bytes - Total allocated size: 24 + 8 = 32 bytes
- DUID value: `0x03` (TDU - Terminator Data Unit) - DUID value: `0x03` (TDU - Terminator Data Unit)
**P25 Message Header Structure (24 bytes):**
| Offset | Length | Field | Description |
|--------|--------|-------|-------------|
| 0-3 | 4 | P25 Tag | "P25D" (0x50323544) |
| 4 | 1 | DUID | 0x03 (TDU) |
| 5 | 1 | Control Byte | Network control flags (at offset 14 in buffer) |
| 6 | 1 | LCO | Link Control Opcode (from last transmission) |
| 7 | 1 | MFId | Manufacturer ID |
| 8-10 | 3 | Source ID | Radio ID that ended transmission |
| 11-13 | 3 | Destination ID | Target talkgroup/radio |
| 14-16 | 3 | Reserved | Reserved bytes |
| 17 | 1 | RSSI | Signal strength |
| 18 | 1 | BER | Bit error rate |
| 19-22 | 4 | Reserved | Reserved bytes |
| 23 | 1 | Count | 0x18 (24) - header size only, no payload follows |
**Raw TDU Packet Example (hexadecimal):**
```
[RTP Header: 12 bytes] [FNE Header: 20 bytes] [P25 Header: 24 bytes] [NO PAYLOAD]
Complete Packet (56 bytes):
90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 01 12 34 56 78 00 00 4E 20 00 18 00 00 00 00 00 00 | 50 32 35 44 03 00 03 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 18
├─────────── RTP (12) ───────────┤ ├──────────────────────── FNE (20) ────────────────────────┤ ├──────────────────────── P25 (24) ─────────────────────────┤
P25 Message Header (NO PAYLOAD FOLLOWS):
50 32 35 44 03 00 03 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 18
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │ │ └──┴──┴──┴──┴─ Count: 0x18 (24) - header only
│ │ │ │ │ │ │ │ │ │ │ │ └────────────────── Reserved (4 bytes)
│ │ │ │ │ │ │ │ │ │ │ └───────────────────── BER: 0x00
│ │ │ │ │ │ │ │ │ │ └──────────────────────── RSSI: 0x7F (127)
│ │ │ │ │ │ │ │ │ └──┴──┴───────────────────── Reserved (3 bytes)
│ │ │ │ │ │ │ └──┴────────────────────────────────────── Dest ID: 0x00CCDDEE (13492718)
│ │ │ │ │ │ └────────────────────────────────────────────────── Src ID: 0x0000AABB (43707)
│ │ │ │ │ └───────────────────────────────────────────────────── MFId: 0x90 (Standard)
│ │ │ │ └──────────────────────────────────────────────────────── LCO: 0x03 (Group Voice)
│ │ │ └─────────────────────────────────────────────────────────── Control: 0x00
│ │ └────────────────────────────────────────────────────────────── DUID: 0x03 (TDU)
└────────┴───────────────────────────────────────────────────────────────── Tag: "P25D" (0x50323544)
Total packet ends at byte 56 - no additional payload bytes after the P25 header. Total packet ends at byte 56 - no additional payload bytes after the P25 header.
```
**Important Note:** **Important Note:**
@ -1463,28 +1448,12 @@ The 45-byte TSDU frame data at offset 24 is **transmitted in its raw over-the-ai
Complete Packet (101 bytes): Complete Packet (101 bytes):
90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 01 12 34 56 78 00 00 4E 20 00 45 00 00 00 00 00 00 | 50 32 35 44 07 00 00 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 2D [45 bytes raw TSDU frame...] 90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 01 12 34 56 78 00 00 4E 20 00 45 00 00 00 00 00 00 | 50 32 35 44 07 00 00 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 2D [45 bytes raw TSDU frame...]
├─────────── RTP (12) ───────────┤ ├──────────────────────── FNE (20) ────────────────────────┤ ├───────────────────────────────── P25 TSDU (69) ────────────────────────────────┤ ├─────────── RTP (12) ────────────┤ ├──────────────────────── FNE (20) ───────────────────────┤ ├───────────────────────────────── P25 TSDU (69) ─────────────────────────────────────────────────────┤
TSDU Message Header (24 bytes):
50 32 35 44 07 00 00 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 2D
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │ │ └──┴──┴──┴──┴─ Count: 0x2D (45)
│ │ │ │ │ │ │ │ │ │ │ │ └────────────────── Reserved
│ │ │ │ │ │ │ │ │ │ │ └───────────────────── BER: 0x00
│ │ │ │ │ │ │ │ │ │ └──────────────────────── RSSI: 0x7F (127)
│ │ │ │ │ │ │ │ │ └──┴──┴───────────────────── Reserved
│ │ │ │ │ │ │ └──┴────────────────────────────────────── Dest ID: 0x00CCDDEE (13492718)
│ │ │ │ │ │ └────────────────────────────────────────────────── Src ID: 0x0000AABB (43707)
│ │ │ │ │ └───────────────────────────────────────────────────── MFId: 0x90 (Standard)
│ │ │ │ └──────────────────────────────────────────────────────── LCO: 0x00 (not applicable for TSDU)
│ │ │ └─────────────────────────────────────────────────────────── Control: 0x00
│ │ └────────────────────────────────────────────────────────────── DUID: 0x07 (TSDU)
└────────┴───────────────────────────────────────────────────────────────── Tag: "P25D" (0x50323544)
TSDU Frame Data (45 bytes starting at offset 24): TSDU Frame Data (45 bytes starting at offset 24):
55 75 F7 FF 5D 7F [NID: 2 bytes] [TSBK: 25 bytes FEC encoded] [Status: 12 bytes] 55 75 F7 FF 5D 7F [NID: 2 bytes] [TSBK: 25 bytes FEC encoded] [Status: 12 bytes]
│ │ └────────────┴────────────────────┴──────────────────────── Raw over-the-air P25 TSDU frame │ │ └────────────┴────────────────────┴──────────────────────── Raw over-the-air P25 TSDU frame
└──────────────┴────────────────────────────────────────────────────────────── Frame Sync pattern └──────────────┴───────────────────────────────────────────────────────────── Frame Sync pattern
``` ```
**TSDU Content Types:** **TSDU Content Types:**
@ -1544,28 +1513,12 @@ The 54-byte TDULC frame data at offset 24 is **transmitted in its raw over-the-a
Complete Packet (110 bytes): Complete Packet (110 bytes):
90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 01 12 34 56 78 00 00 4E 20 00 4E 00 00 00 00 00 00 | 50 32 35 44 0F 00 03 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 36 [54 bytes raw TDULC frame...] 90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 01 12 34 56 78 00 00 4E 20 00 4E 00 00 00 00 00 00 | 50 32 35 44 0F 00 03 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 36 [54 bytes raw TDULC frame...]
├─────────── RTP (12) ───────────┤ ├──────────────────────── FNE (20) ────────────────────────┤ ├──────────────────────────────── P25 TDULC (78) ─────────────────────────────────┤ ├─────────── RTP (12) ────────────┤ ├──────────────────────── FNE (20) ───────────────────────┤ ├──────────────────────────────── P25 TDULC (78) ──────────────────────────────────────────────────────┤
TDULC Message Header (24 bytes):
50 32 35 44 0F 00 03 90 00 00 AA BB 00 CC DD EE 00 00 00 7F 00 00 00 00 36
│ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │
│ │ │ │ │ │ │ │ │ │ │ │ │ └──┴──┴──┴──┴─ Count: 0x36 (54)
│ │ │ │ │ │ │ │ │ │ │ │ └────────────────── Reserved
│ │ │ │ │ │ │ │ │ │ │ └───────────────────── BER: 0x00
│ │ │ │ │ │ │ │ │ │ └──────────────────────── RSSI: 0x7F (127)
│ │ │ │ │ │ │ │ │ └──┴──┴───────────────────── Reserved
│ │ │ │ │ │ │ └──┴────────────────────────────────────── Dest ID: 0x00CCDDEE (13492718)
│ │ │ │ │ │ └────────────────────────────────────────────────── Src ID: 0x0000AABB (43707)
│ │ │ │ │ └───────────────────────────────────────────────────── MFId: 0x90 (Standard)
│ │ │ │ └──────────────────────────────────────────────────────── LCO: 0x03 (Group Voice)
│ │ │ └─────────────────────────────────────────────────────────── Control: 0x00
│ │ └────────────────────────────────────────────────────────────── DUID: 0x0F (TDULC)
└────────┴───────────────────────────────────────────────────────────────── Tag: "P25D" (0x50323544)
TDULC Frame Data (54 bytes starting at offset 24): TDULC Frame Data (54 bytes starting at offset 24):
55 75 F7 FF 5D 7F [NID: 2 bytes] [LC: 36 bytes FEC encoded] [Status: 10 bytes] 55 75 F7 FF 5D 7F [NID: 2 bytes] [LC: 36 bytes FEC encoded] [Status: 10 bytes]
│ │ └────────────┴──────────────────────┴─────────────────────── Raw over-the-air P25 TDULC frame │ │ └────────────┴──────────────────────┴─────────────────────── Raw over-the-air P25 TDULC frame
└──────────────┴──────────────────────────────────────────────────────────────── Frame Sync pattern └──────────────┴────────────────────────────────────────────────────────────── Frame Sync pattern
``` ```
**TDULC Link Control Content:** **TDULC Link Control Content:**
@ -1639,10 +1592,6 @@ The encapsulated Phase 2 format is fixed-length:
``` ```
[RTP: 12 bytes] [FNE: 20 bytes] [P25 Phase 2: 66 bytes] [RTP: 12 bytes] [FNE: 20 bytes] [P25 Phase 2: 66 bytes]
Complete Packet (98 bytes):
[RTP 12] [FNE 20] [P25 header 24 with slot/DUID in byte 19] [40 bytes raw P25 P2 payload] [packet pad]
├─────────── RTP (12) ───────────┤ ├──────────────────────── FNE (20) ────────────────────────┤ ├──────────────────────────── P25 P2 (66) ────────────────────────────┤
P25 Phase 2 payload breakdown: P25 Phase 2 payload breakdown:
"P25D" | common P25 header fields | controlByte @ 14 | slot/DUID @ 19 | count=0x40 @ 23 | 40 bytes raw P25 Phase 2 payload "P25D" | common P25 header fields | controlByte @ 14 | slot/DUID @ 19 | count=0x40 @ 23 | 40 bytes raw P25 Phase 2 payload
``` ```
@ -1700,25 +1649,19 @@ The NXDN network packet uses the TAG_NXDN_DATA identifier and includes the 48-by
Complete Packet (102 bytes): Complete Packet (102 bytes):
90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 00 12 34 56 78 00 00 4E 20 00 46 00 00 00 00 00 00 | 4E 58 44 44 02 00 10 00 00 20 00 00 01 00 00 00 00 00 00 00 00 00 00 30 [48 bytes NXDN frame...] 90 FE 00 2A 00 00 1F 40 00 00 4E 20 | A3 5C 00 00 12 34 56 78 00 00 4E 20 00 46 00 00 00 00 00 00 | 4E 58 44 44 02 00 10 00 00 20 00 00 01 00 00 00 00 00 00 00 00 00 00 30 [48 bytes NXDN frame...]
├─────────── RTP (12) ───────────┤ ├──────────────────────── FNE (20) ────────────────────────┤ ├─────────────────────────────────── NXDN (70) ─────────────────────────────────┤ ├─────────── RTP (12) ────────────┤ ├──────────────────────── FNE (20) ───────────────────────┤ ├─────────────────────────────────── NXDN (70) ────────────────────────────────────────────────┤
NXDN Payload breakdown: NXDN Payload breakdown:
4E 58 44 44 02 00 10 00 00 20 00 00 01 00 00 00 00 00 00 00 00 00 00 30 [48 bytes NXDN frame data...] 4E 58 44 44 02 00 10 00 00 20 00 00 00 00 00 01 00 00 00 00 00 00 00 30 [48 bytes NXDN frame data...]
│ │ │ │ │ │ │ │ │ └──────────┴──────────┴─────┤ │ │ │ │ │ │ │ │ │ │ │ │ │ └──── NXDN Count: 0x30 (48)
│ │ │ │ │ │ │ │ └───────────────────────────────── Group: 0x00 (private call) │ │ │ │ │ │ │ │ │ │ │ └──────────────────┴────── Reserved
│ │ │ │ │ │ │ └──────────────────────────────────── Control: 0x01 │ │ │ │ │ │ │ │ │ │ └──────────────────────────── Group: 0x01 (group call)
│ │ │ │ │ └─[Reserved 3] │ │ │ │ │ │ │ │ │ └─────────────────────────────── Control: 0x00
│ │ │ │ └─[DestID 3rd byte]──────────────────────────────── Dest ID: 0x200000 (2097152) │ │ │ │ │ │ │ └─────┴────────────────────────────────── Reserved
│ │ │ └─[DestID 2nd byte] │ │ │ │ │ └─────┴─────────────────────────────────────────── Dest ID: 0x002000 (8192)
│ │ └─[DestID 1st byte] │ │ │ └─────┴──────────────────────────────────────────────────── Src ID: 0x001000 (4096)
│ └─[SrcID 3rd byte]──────────────────────────────────────────────── Src ID: 0x001000 (4096) │ │ └───────────────────────────────────────────────────────────── Msg Type: 0x02 (RTCH)
│ └─[SrcID 2nd byte] └────────┴──────────────────────────────────────────────────────────────── Tag: "NXDD" (0x4E584444)
│ └─[SrcID 1st byte]
│ └──────────────────────────────────────────────────────────────── Msg Type: 0x02 (RTCH)
└───────────────────────────────────────────────────────────────────────── Tag: "NXDD" (0x4E584444)
└────────────────────────────────────────────────────────────────── Reserved (7 bytes)
└─ Count: 0x30 (48)
(NXDN frame at offset 24)
``` ```
**NXDN Message Types:** **NXDN Message Types:**
@ -1781,7 +1724,6 @@ The analog audio packet uses the `TAG_ANALOG_DATA` identifier (`"ANOD"`) and con
Complete Packet (376 bytes): Complete Packet (376 bytes):
[RTP 12] [FNE 20] ["ANOD" + header bytes + 320 bytes audio + 4 byte trailer] [RTP 12] [FNE 20] ["ANOD" + header bytes + 320 bytes audio + 4 byte trailer]
├─────────── RTP (12) ───────────┤ ├──────────────────────── FNE (20) ────────────────────────┤ ├────────────────────────────────── Analog (344) ──────────────────────────────────┤
Analog Payload breakdown: Analog Payload breakdown:
"ANOD" | Seq | SrcID | DstID | Reserved | Control | FrameType/Group | Reserved | 320 bytes audio | 4 byte trailer "ANOD" | Seq | SrcID | DstID | Reserved | Control | FrameType/Group | Reserved | 320 bytes audio | 4 byte trailer

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