--- title: "W55RP20-S2E Long connection to MQTT" url: "https://maker.wiznet.io/forum/15941" markdown_url: "https://maker.wiznet.io/forum/15941/md" type: "Forum topic" category: "Serial-to-Ethernet & ConfigTool" author: "pyszny21" created: "2025-11-18T22:25:00+09:00" last_activity: "2025-11-19T16:09:03+09:00" language: "en" tags: ["AWS IoT Core", "W55RP20"] views: 5 replies: 1 source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)" --- # W55RP20-S2E Long connection to MQTT ## Question Asked by pyszny21 on 2025-11-18 in Serial-to-Ethernet & ConfigTool. Hi everyone, I'm having a problem with the W55RP20-S2E module. The connection time to the broker is about 20 seconds, sometimes less, but usually 20 seconds. I'm wondering if this is normal? I've tested the device on versions 1.1.9 and 1.2.0, and they work similarly. I use three certificates to authenticate with the broker. I've analyzed the logs, and what puzzles me most is this fragment, which takes over 12 seconds: (10:11:38.811) (12.856) [SEG] <14992> proc_SEG_mqtts_client 834 [C0] : > SEG:TCP_CLIENT_OVER_TLS_MODE: TCP CLIENT CONNECTED. Is there a way to speed this up? Is this a feature of this module? I have uploaded the entire log file as an attachment. thank you for your help Attachments: - [(101121.616) (0.000) ˙˙\[INFO\] main.txt](https://maker.wiznet.io/forum/getAttach.asp?aidx=309) ## Replies ### Reply 1 by pyszny21, 2025-11-19 Hi, thank you for the quick reply. answers to questions - Firmware version (you already noted 1.1.9 and 1.2.0) - I tested firmware 1.1.9 and 1.2.0 from this website - Broker type/version and whether session resumption is enabled - I used EMQX broker - The device connects to the broker only to send data. There is no way to resume the session. - Certificate chain details (root/intermediate length, key type/size) - I use 3 certificates (CA (Certificate Authority), device certificate, and Device private key (RSA 2048) - Whether DNS or IP is used, and measured DNS latency - I use IP adress - Your SSL receive timeout (SO) and reconnection interval (RI) values SO 2000 RI 100 thank for help --- Source: https://maker.wiznet.io/forum/15941