---
title: "PUT /subscription/frames"
method: PUT
path: "/subscription/frames"
---

# PUT /subscription/frames

`PUT /subscription/frames`

Forward MAC frames to a specified destination (subscribe to a frame stream).

## Request body

- FrameSubscription — A subscription to configure a FAN device to echo received MAC frames to a designated UDP listener's IP address / port number. The PCAP Next Generation (pcapng) Capture File Format (draft-tuexen-opsawg-pcapng) MUST be used to encapsulate forwarded frames, with the blocks sent as the data portion of a UDP datagram. When the subscription starts, the TBU MUST send a Section Header Block followed by an Interface Description Block indicating a LinkType of LINKTYPE_IEEE802_15_4_NOFCS (230). Forwarded frames MUST be provided in Enhanced Packet Blocks. Only frames that are received by the device, have a valid FCS, have passed security, and are passed to upper layer are forwarded. Further, forwarded frames MUST be unencrypted, and MUST have the Auxiliary Security Header / Security Level field set to None (0).
  - `subscriptionMode` 'Start' | 'Stop', required — The listener starts or stops a frame subscription/forwarding. Start means start forwarding frames and Stop means cease forwarding frames. If the device implements /subscription/frames/hash, the device MUST maintain a SHA256 hash of all PCAPNG data forwarded between the acceptance of Start and Stop (inclusive), with this hash initialized to 0 upon reception of Start.
  - `fwdAddress` string, required — The IPv4 or IPv6 address of the listener. IPv6 address strings are formatted per RFC 5952.
  - `fwdPort` integer, required — The port number of the listener.

## Response `200`

Listener successfully subscribed.

## Other responses

- `default` — Unknown error occurred.

---

[API](https://skmtc.net/siliconlabs/apis/tbu-api.md) · [All operations](https://skmtc.net/siliconlabs/apis/tbu-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/siliconlabs/tbu-api/versions/8475de394ee2/schema)