raz/mike pointed out that getetx returns etx*10 not etx*100

[tinyos-2.x.git] / doc / txt / tep123.txt

diff --git a/doc/txt/tep123.txt b/doc/txt/tep123.txt
index 96af8a42883fc159c0972a0fe68247ee7fb23709..477d87dc30f3645e81918cea8f646445705e6db2 100644 (file)
--- a/doc/txt/tep123.txt
+++ b/doc/txt/tep123.txt
@@ -72,8 +72,8 @@ ETX of its link to its parent. This additive measure assumes that
 nodes use link-level retransmissions.  Given a choice of valid routes,
 CTP SHOULD choose the one with the lowest ETX value. CTP represents
 ETX values as 16-bit fixed-point real numbers with a precision of
-hundredths. An ETX value of 451, for example, represents an ETX of
-4.51, while an ETX value of 109 represents an ETX of 1.09.
+hundredths. An ETX value of 45, for example, represents an ETX of 4.5,
+while an ETX value of 10 represents an ETX of 1.
 
 Routing loops are a problem that can emerge in a CTP network. Routing
 loops generally occur when a node choose a new route that has a
@@ -116,23 +116,23 @@ to do so.
 The CTP data frame format is as follows::
 
                            1            
-       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      |C|P| reserved  |      THL        |
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      |              ETX                |
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      |             origin              |                 
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      |     seqno     |   collect_id    |    
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |P|C| reserved  |      THL      |
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |              ETX              |
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |             origin            |                 
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |     seqno     |   collect_id  |    
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |    data ... 
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 
 Field definitions are as follows:
 
-  * C: Congestion notification. If a node drops a CTP data frame, it MUST set the C field on the next data frame it transmits.
   * P: Routing pull. The P bit allows nodes to request routing information from other nodes. If a node with a valid route hears a packet with the P bit set, it SHOULD transmit a routing frame in the near future.
+  * C: Congestion notification. If a node drops a CTP data frame, it MUST set the C field on the next data frame it transmits.
   * THL: Time Has Lived. When a node generates a CTP data frame, it MUST set THL to 0. When a node receives a CTP data frame, it MUST increment the THL. If a node receives a THL of 255, it increments it to 0.
   * ETX: The ETX routing metric of the single-hop sender. When a node transmits a CTP data frame, it MUST put the ETX value of its route through the single-hop destination in the ETX field.  If a node receives a packet with a lower gradient than its own, then it MUST schedule a routing frame in the near future.
   * origin: The originating address of the packet. A node forwarding a data frame MUST NOT modify the origin field.
@@ -159,19 +159,19 @@ acknowledgments enabled.
 The CTP routing frame format is as follows::
 
                            1            
-       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      |C|P| reserved  |      parent     |
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-      |     parent    |       ETX       |    
-      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |P|C| reserved  |     parent    |
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+      |     parent    |      ETX      |    
+      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |      ETX      |          
       +-+-+-+-+-+-+-+-+
 
 The fields are as follows:
   
-  * C: Congestion notification. If a node drops a CTP data frame, it MUST set the C field on the next routing frame it transmits.
   * P: Same as data frame.
+  * C: Congestion notification. If a node drops a CTP data frame, it MUST set the C field on the next routing frame it transmits.
   * parent: The node's current parent.
   * metric: The node's current routing metric value.