eth/protocols/snap: lower the packet size to avoid overloading link

eth/protocols/snap/sync.go

@@ -52,7 +52,7 @@ var (
 
 const (
 	// maxRequestSize is the maximum number of bytes to request from a remote peer.
-	maxRequestSize = 512 * 1024
+	maxRequestSize = 128 * 1024
 
 	// maxStorageSetRequestCount is the maximum number of contracts to request the
 	// storage of in a single query. If this number is too low, we're not filling
@@ -74,7 +74,7 @@ const (
 	// a single query. If this number is too low, we're not filling responses fully
 	// and waste round trip times. If it's too high, we're capping responses and
 	// waste bandwidth.
-	maxTrieRequestCount = 512
+	maxTrieRequestCount = 256
 )
 
 var (