SimTX API/Packets/Ping: Difference between revisions
Protocol v25 reference |
Remove development history and server internals |
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== Example == | == Example == | ||
Complete frames, including the varint length prefix | Complete frames, including the varint length prefix. | ||
'''<code>ping</code>''' (client to server, 12 bytes): | '''<code>ping</code>''' (client to server, 12 bytes): | ||
Latest revision as of 17:16, 24 October 2026
| Frame | ClientFrame, field 2
|
|---|---|
| Member | ping
|
| Direction | Client → server |
| Session | All roles |
| Roles | All roles, any time after the hello. |
| Permission | None |
| Answered by | Pong |
| Defined in | frames.proto
|
Ping asks the server for a Pong. Use it to measure the round-trip time, to estimate the offset between the client and server clocks, or to check that an otherwise idle connection is alive.
Definition[edit | edit source]
message Ping { int64 nonce = 1; int64 client_time_ms = 2; }
Fields[edit | edit source]
| # | Field | Type | Description |
|---|---|---|---|
| 1 | nonce |
int64 |
Any value chosen by the client; echoed in the Pong. |
| 2 | client_time_ms |
int64 |
Client clock when sent, Unix ms; echoed. |
Behaviour[edit | edit source]
- Every role accepts it at any time after the ServerHello.
- The server answers each ping with one pong. Pongs can arrive between any other frames, so match them by
nonce. - Pings are cheap, but there is no reason to send more than one every few seconds.
Example[edit | edit source]
Complete frames, including the varint length prefix.
ping (client to server, 12 bytes):
0B frame length 11
12 09 ping (Ping), 9 bytes
08 63 nonce = 99
10 80 94 83 B9 97 34 client_time_ms = 1793000000000