Probing coap://coap.me/large

coap://coap.me/large    [revalidate: /etag=2737638792792008104/accept=0/coap://coap.me/large]

:etag	2737638792792008104 = 0x25fe0bfa37b265a8
:block2	211 = 0xd3

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Ver| T | TKL | Code | Message ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Token (if any, TKL bytes) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Options (if any) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|1 1 1 1 1 1 1 1| Payload (if any) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

[...]

Token Length (TKL): 4-bit unsigned integer. Indicates the length of
the variable-length Token field (0-8 bytes). Lengths 9-15 are
reserved, MUST NOT be sent, and MUST be processed as a message
format error.

Code: 8-bit unsigned integer, split into a 3-bit class (most
significant bits) and a 5-bit detail (least significant bits),
documented as c.dd where c is a digit from 0 to 7 for the 3-bit
subfield and dd are two digits from 00 to 31 for the 5-bit
subfield. The class can indicate a request (0), a success
response (2), a client error response (4), or a server error
response (5). (All other class values are reserved.) As a
special case, Code 0.00 indicates an Empty message. In case of a
request, the Code field indicates the Request Method; in case of a
response a Response Code. Possible values are maintained in the
CoAP Code Registries (Section 12.1). The semantics of requests
and responses are defined in Section 5.