diff --git a/services/tunnelbroker/src/constants.rs b/services/tunnelbroker/src/constants.rs
new file mode 100644
index 000000000..cb8385c66
--- /dev/null
+++ b/services/tunnelbroker/src/constants.rs
@@ -0,0 +1,2 @@
+pub const GRPC_TX_QUEUE_SIZE: usize = 32;
+pub const GRPC_PING_INTERVAL_MS: u64 = 3000;
diff --git a/services/tunnelbroker/src/main.rs b/services/tunnelbroker/src/main.rs
index 66b13bc1c..ab42a99ca 100644
--- a/services/tunnelbroker/src/main.rs
+++ b/services/tunnelbroker/src/main.rs
@@ -1,11 +1,13 @@
+pub mod constants;
+
 #[cxx::bridge]
 mod ffi {
   unsafe extern "C++" {
     include!("tunnelbroker/src/libcpp/Tunnelbroker.h");
     pub fn initialize();
   }
 }
 
 pub fn main() {
   ffi::initialize();
 }