diff --git a/src/shearwater_common.c b/src/shearwater_common.c
index 68d7b46..a6b454d 100644
--- a/src/shearwater_common.c
+++ b/src/shearwater_common.c
@@ -144,64 +144,63 @@ static dc_status_t
 shearwater_common_slip_write (shearwater_common_device_t *device, const unsigned char data[], unsigned int size)
 {
 	dc_status_t status = DC_STATUS_SUCCESS;
-	const unsigned char end[] = {END};
-	const unsigned char esc_end[] = {ESC, ESC_END};
-	const unsigned char esc_esc[] = {ESC, ESC_ESC};
 	unsigned char buffer[32];
 	unsigned int nbytes = 0;
 
 #if 0
 	// Send an initial END character to flush out any data that may have
 	// accumulated in the receiver due to line noise.
-	status = dc_iostream_write (device->iostream, end, sizeof (end), NULL);
-	if (status != DC_STATUS_SUCCESS) {
-		return status;
-	}
+	buffer[nbytes++] = END;
 #endif
 
 	for (unsigned int i = 0; i < size; ++i) {
-		const unsigned char *seq = NULL;
-		unsigned int len = 0;
-		switch (data[i]) {
-		case END:
-			// Escape the END character.
-			seq = esc_end;
-			len = sizeof (esc_end);
-			break;
-		case ESC:
-			// Escape the ESC character.
-			seq = esc_esc;
-			len = sizeof (esc_esc);
-			break;
-		default:
-			// Normal character.
-			seq = data + i;
-			len = 1;
-			break;
+		unsigned char c = data[i];
+
+		if (c == END || c == ESC) {
+			// Append the escape character.
+			buffer[nbytes++] = ESC;
+
+			// Flush the buffer if necessary.
+			if (nbytes >= sizeof(buffer)) {
+				status = dc_iostream_write (device->iostream, buffer, nbytes, NULL);
+				if (status != DC_STATUS_SUCCESS) {
+					ERROR (device->base.context, "Failed to send the packet.");
+					return status;
+				}
+
+				nbytes = 0;
+			}
+
+			// Escape the character.
+			if (c == END) {
+				c = ESC_END;
+			} else {
+				c = ESC_ESC;
+			}
 		}
 
+		// Append the character.
+		buffer[nbytes++] = c;
+
 		// Flush the buffer if necessary.
-		if (nbytes + len + sizeof(end) > sizeof(buffer)) {
+		if (nbytes >= sizeof(buffer)) {
 			status = dc_iostream_write (device->iostream, buffer, nbytes, NULL);
 			if (status != DC_STATUS_SUCCESS) {
+				ERROR (device->base.context, "Failed to send the packet.");
 				return status;
 			}
 
 			nbytes = 0;
 		}
-
-		// Append the escaped character.
-		memcpy(buffer + nbytes, seq, len);
-		nbytes += len;
 	}
 
 	// Append the END character to indicate the end of the packet.
-	memcpy(buffer + nbytes, end, sizeof(end));
-	nbytes += sizeof(end);
+	buffer[nbytes++] = END;
 
 	// Flush the buffer.
 	status = dc_iostream_write (device->iostream, buffer, nbytes, NULL);
 	if (status != DC_STATUS_SUCCESS) {
+		ERROR (device->base.context, "Failed to send the packet.");
 		return status;
 	}
 
@@ -213,7 +212,8 @@ static dc_status_t
 shearwater_common_slip_read (shearwater_common_device_t *device, unsigned char data[], unsigned int size, unsigned int *actual)
 {
 	dc_status_t status = DC_STATUS_SUCCESS;
-	unsigned int received = 0;
+	unsigned int escaped = 0;
+	unsigned int nbytes = 0;
 
 	// Read bytes until a complete packet has been received. If the
 	// buffer runs out of space, bytes are dropped. The caller can
@@ -225,28 +225,37 @@ shearwater_common_slip_read (shearwater_common_device_t *device, unsigned char d
 		// Get a single character to process.
 		status = dc_iostream_read (device->iostream, &c, 1, NULL);
 		if (status != DC_STATUS_SUCCESS) {
+			ERROR (device->base.context, "Failed to receive the packet.");
 			return status;
 		}
 
-		switch (c) {
-		case END:
-			// If it's an END character then we're done.
-			// As a minor optimization, empty packets are ignored. This
-			// is to avoid bothering the upper layers with all the empty
-			// packets generated by the duplicate END characters which
-			// are sent to try to detect line noise.
-			if (received)
-				goto done;
-			else
-				break;
-		case ESC:
-			// If it's an ESC character, get another character and then
-			// figure out what to store in the packet based on that.
-			status = dc_iostream_read (device->iostream, &c, 1, NULL);
-			if (status != DC_STATUS_SUCCESS) {
-				return status;
+		if (c == END || c == ESC) {
+			if (escaped) {
+				// If the END or ESC characters are escaped, then we
+				// have a protocol violation, and an error is reported.
+				ERROR (device->base.context, "SLIP frame escaped the special character %02x.", c);
+				return DC_STATUS_PROTOCOL;
 			}
 
+			if (c == END) {
+				// If it's an END character then we're done.
+				// As a minor optimization, empty packets are ignored. This
+				// is to avoid bothering the upper layers with all the empty
+				// packets generated by the duplicate END characters which
+				// are sent to try to detect line noise.
+				if (nbytes) {
+					goto done;
+				}
+			} else {
+				// If it's an ESC character, get another character and then
+				// figure out what to store in the packet based on that.
+				escaped = 1;
+			}
+
+			continue;
+		}
+
+		if (escaped) {
 			// If it's not one of the two escaped characters, then we
 			// have a protocol violation. The best bet seems to be to
 			// leave the byte alone and just stuff it into the packet.
@@ -257,24 +266,29 @@ shearwater_common_slip_read (shearwater_common_device_t *device, unsigned char d
 			case ESC_ESC:
 				c = ESC;
 				break;
+			default:
+				break;
 			}
-			// Fall-through!
-		default:
-			if (received < size)
-				data[received] = c;
-			received++;
+
+			escaped = 0;
 		}
+
+		if (nbytes < size)
+			data[nbytes] = c;
+		nbytes++;
 	}
 
 done:
 
-	if (received > size)
+	if (nbytes > size) {
+		ERROR (device->base.context, "Insufficient buffer space available.");
 		return DC_STATUS_PROTOCOL;
+	}
 
 	if (actual)
-		*actual = received;
+		*actual = nbytes;
 
-	return DC_STATUS_SUCCESS;
+	return status;
 }