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<?xml-stylesheet type="text/xsl" href="https://devzone.nordicsemi.com/cfs-file/__key/system/syndication/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>bt_att: No ATT channel for MTU 27</title><link>https://devzone.nordicsemi.com/f/nordic-q-a/111363/bt_att-no-att-channel-for-mtu-27</link><description>I am use sample &amp;quot;Bluetooth: Peripheral HR&amp;quot; as the base app 
 and added these settings to `prj.conf` on both central and peripheral sides 
 
 
 
 
 
 
 
 but I still got the error 
 
 [00:03:00.037,811] &amp;lt;wrn&amp;gt; bt_att: No ATT channel for MTU 27 [00:03:00</description><dc:language>en-US</dc:language><generator>Telligent Community 13</generator><lastBuildDate>Fri, 24 May 2024 11:47:44 GMT</lastBuildDate><atom:link rel="self" type="application/rss+xml" href="https://devzone.nordicsemi.com/f/nordic-q-a/111363/bt_att-no-att-channel-for-mtu-27" /><item><title>RE: bt_att: No ATT channel for MTU 27</title><link>https://devzone.nordicsemi.com/thread/485798?ContentTypeID=1</link><pubDate>Fri, 24 May 2024 11:47:44 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:8079d95b-e308-45f1-a596-5d6388eb9a7b</guid><dc:creator>Edvin</dc:creator><description>&lt;p&gt;Hello,&lt;/p&gt;
&lt;p&gt;Both devices can initiate an MTU exchange. There is not really a rule here. They will then start negotiating the MTU size, and the one that has the lowest supported MTU will have the final saying.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;As for connections parameters in general, it depends on which one. Connection interval is decided by the central, but the peripheral can initiate an MTU negotiation. However, in that case the central has the final saying.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Edvin&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: bt_att: No ATT channel for MTU 27</title><link>https://devzone.nordicsemi.com/thread/485569?ContentTypeID=1</link><pubDate>Thu, 23 May 2024 08:46:55 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:1d4c0208-693b-465e-940f-48b1f2893234</guid><dc:creator>LongQi</dc:creator><description>&lt;p&gt;&lt;span&gt;MTU and conn parameters are changed from the peripheral side in the example.&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;Can MTU and conn parameters be changed from both of central and peripheral side?&amp;nbsp;&lt;/p&gt;
&lt;p&gt;which side should be the one to change it? which one is&amp;nbsp;more standard?&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: bt_att: No ATT channel for MTU 27</title><link>https://devzone.nordicsemi.com/thread/485237?ContentTypeID=1</link><pubDate>Tue, 21 May 2024 22:26:38 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:4235394e-8836-4f44-b30b-86e3fbb2f874</guid><dc:creator>Edvin</dc:creator><description>&lt;p&gt;Hello,&lt;/p&gt;
&lt;p&gt;To increase the MTU properly, I suggest you check out the Bluetooth Low Energy Fundamentals course on Nordic Developer Academy. Particularly &lt;a href="https://academy.nordicsemi.com/courses/bluetooth-low-energy-fundamentals/lessons/lesson-3-bluetooth-le-connections/topic/blefund-lesson-3-exercise-2/"&gt;Lesson 3 Exercise 2&lt;/a&gt;, step 10 and 11 are relevant.&lt;/p&gt;
&lt;p&gt;Give it a go, and let me know if you are still stuck.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Edvin&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>