Skills › Scientific Agent Skills › markdown-mermaid-writing › packet.md

packet.md

65 lines · skills/markdown-mermaid-writing/references/diagrams/packet.md at 5f2bc03

1

3# Packet Diagram

5> **Back to [Style Guide](../mermaid_style_guide.md)** — Read the style guide first for emoji, color, and accessibility rules.

7**Syntax keyword:** `packet-beta`

8**Best for:** Network protocol headers, data structure layouts, binary format documentation, bit-level specifications

9**When NOT to use:** General data models (use [ER](er.md)), system architecture (use [C4](c4.md) or [Architecture](architecture.md))

11> **Accessibility:** Mermaid 12.0.0 emits `accTitle`/`accDescr` for this type. Keep a visible description and verify older destination renderers.

13---

Packet Diagram

Back to Style Guide — Read the style guide first for emoji, color, and accessibility rules.

Syntax keyword: packet-beta Best for: Network protocol headers, data structure layouts, binary format documentation, bit-level specifications When NOT to use: General data models (use ER), system architecture (use C4 or Architecture)

Accessibility: Mermaid 12.0.0 emits accTitle/accDescr for this type. Keep a visible description and verify older destination renderers.

Raw lines 1 to 14

15## Exemplar Diagram

17_Packet diagram showing the fixed 160-bit TCP header portion with field sizes in bits (options and payload omitted):_

19```mermaid

20packet-beta

21 accTitle: Packet Example

22 accDescr: Illustrative packet diagram; the surrounding text describes its data and relationships.

23 0-15: "Source Port"

24 16-31: "Destination Port"

25 32-63: "Sequence Number"

26 64-95: "Acknowledgment Number"

27 96-99: "Data Offset"

28 100-103: "Reserved"

29 104-111: "Flags (CWR,ECE,URG,ACK,PSH,RST,SYN,FIN)"

30 112-127: "Window Size"

31 128-143: "Checksum"

32 144-159: "Urgent Pointer"

33```

35---

Exemplar Diagram

Packet diagram showing the fixed 160-bit TCP header portion with field sizes in bits (options and payload omitted):

packet-beta
    accTitle: Packet Example
    accDescr: Illustrative packet diagram; the surrounding text describes its data and relationships.
    0-15: "Source Port"
    16-31: "Destination Port"
    32-63: "Sequence Number"
    64-95: "Acknowledgment Number"
    96-99: "Data Offset"
    100-103: "Reserved"
    104-111: "Flags (CWR,ECE,URG,ACK,PSH,RST,SYN,FIN)"
    112-127: "Window Size"
    128-143: "Checksum"
    144-159: "Urgent Pointer"

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37## Tips

39- Ranges are inclusive `start-end:` bit offsets (0-indexed). A `0-15` field is 16 bits

40- The TCP example follows [RFC 9293 section 3.1](https://www.rfc-editor.org/rfc/rfc9293.html#section-3.1); state byte/bit order and optional fields for any real protocol

41- Keep field labels concise — abbreviate if needed

42- Use for any fixed-width binary format, not just network packets

43- Row width defaults to 32 bits — fields wrap naturally

44- **Always** pair with a Markdown text description above for screen readers

46---

Tips

Ranges are inclusive start-end: bit offsets (0-indexed). A 0-15 field is 16 bits
The TCP example follows RFC 9293 section 3.1; state byte/bit order and optional fields for any real protocol
Keep field labels concise — abbreviate if needed
Use for any fixed-width binary format, not just network packets
Row width defaults to 32 bits — fields wrap naturally
Always pair with a Markdown text description above for screen readers

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48## Template

50_Description of the protocol or data format and its field structure:_

52```mermaid

53packet-beta

54 accTitle: Packet Example

55 accDescr: Illustrative packet diagram; the surrounding text describes its data and relationships.

56 0-7: "Field A"

57 8-15: "Field B"

58 16-31: "Field C"

59 32-63: "Field D"

60```

Template

Description of the protocol or data format and its field structure:

packet-beta
    accTitle: Packet Example
    accDescr: Illustrative packet diagram; the surrounding text describes its data and relationships.
    0-7: "Field A"
    8-15: "Field B"
    16-31: "Field C"
    32-63: "Field D"

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63## Verified reference

65Syntax examples reviewed against [official Mermaid documentation](https://mermaid.js.org/syntax/packet.html) and rendered with Mermaid 12.0.0 (2026-10-01). Check the destination version; appearance and accessibility are not guaranteed by a successful parse.

Verified reference

Syntax examples reviewed against official Mermaid documentation and rendered with Mermaid 12.0.0 (2026-10-01). Check the destination version; appearance and accessibility are not guaranteed by a successful parse.

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