diff --git a/app/src/main/assets/config b/app/src/main/assets/config
index 00cd52c2..ce324210 100644
--- a/app/src/main/assets/config
+++ b/app/src/main/assets/config
@@ -9,6 +9,7 @@ audio_player opensles,nil
 audio_source opensles,nil
 audio_alert opensles,nil
 audio_level no
+audio_buffer 20-300
 audio_buffer_mode adaptive
 ausrc_format s16
 auenc_format s16
@@ -16,6 +17,7 @@ auplay_format s16
 audec_format s16
 rtp_tos 184
 jitter_buffer_type adaptive
+jitter_buffer_delay 0-20
 rtp_stats yes
 dyn_dns yes
 module opus.so
diff --git a/app/src/main/kotlin/com/tutpro/baresip/Config.kt b/app/src/main/kotlin/com/tutpro/baresip/Config.kt
index 491e8663..12fd7227 100644
--- a/app/src/main/kotlin/com/tutpro/baresip/Config.kt
+++ b/app/src/main/kotlin/com/tutpro/baresip/Config.kt
@@ -94,12 +94,12 @@ object Config {
         if (!config.contains("audio_buffer_mode"))
             config = "${config}audio_buffer_mode adaptive\n"
 
-        removeVariable("audio_buffer")  // use default 20-160
+        replaceVariable("audio_buffer", "20-300")
 
         if (!config.contains("jitter_buffer_type"))
             config = "${config}jitter_buffer_type adaptive\n"
 
-        removeVariable("jitter_buffer_delay")  // use default 5-10
+        replaceVariable("jitter_buffer_delay", "0-20")
 
         if (config.contains("contacts_mode")) {
             BaresipService.contactsMode = variable("contacts_mode")[0].lowercase()