Spelling and style corrections to the OSPF section.

1 files changed, 78 insertions, 75 deletions

diff --git a/doc/bird.sgml b/doc/bird.sgml
index 7099ffb..25cc2d5 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -879,34 +879,38 @@ protocol kernel {		# Secondary routing table
 
 <sect1>Introduction
 
-<p>Open Shortest Path First (OSPF) is quite complex interior gateway
-protocol.  Today's version for IPv4 is 2 and it's defined in RFC 2328<htmlurl
-url="ftp://ftp.rfc-editor.org/in-notes/rfc2328.txt">. It's based on
-link-state of SPF technology. Each router maintains a database
-describing the Autonomous System's topology. Each participating router has
-has an identical database and all routers run the exact same algorithm
-calculatin shortest path tree with themselves as roots, in parallel.
-OSPF chooses the least cost path as the best path. In OSPF, the
-Autonomous System can be splitted into more areas. Topology
-of such area is hidden to the rest of the Autonomous System. This enables
-a reduction in routing traffic as well as protection other areas from bad
-routing data. Unfortunatelly multiple OSPF areas are not fully supported
-in this version of BIRD. Another very important feature of OSPF is that
-it can keep routing information from other protocols (like static or BGP)
-in it's link-state database as external routes. Each external route can
-be tagged by the advertising router, enabling the passing of additional
-information between routers on the boundary of the Autonomous System.
-
-<p>OSPF quickly detects topological changes in the Autonomous System (such
+<p>Open Shortest Path First (OSPF) is a quite complex interior gateway
+protocol. The current IPv4 version (OSPFv2) is defined in RFC 2328
+<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2328.txt">. It's a link
+state (a.k.a. shortest path first) protocol -- Each router maintains a database
+describing the autonomous system's topology. Each participating router
+has an identical copy of the database and all routers run the same algorithm
+calculating a shortest path tree with themselves as a root.
+OSPF choses the least cost path as the best path.
+
+<p>In OSPF, the autonomous system can be split to several areas in order
+to reduce the amount of resources consumed for exchanging the routing
+information and to protect the other areas from incorrect routing data.
+Topology of the area is hidden to the rest of the autonomous system.
+Unfortunatelly multiple OSPF areas are not yet fully supported
+by this version of BIRD and neither is the IPv6 version (OSPFv3).
+
+<p>Another very important feature of OSPF is that
+it can keep routing information from other protocols (like Static or BGP)
+in its link state database as external routes. Each external route can
+be tagged by the advertising router, making possible to pass additional
+information between routers on the boundary of the autonomous system.
+
+<p>OSPF quickly detects topological changes in the autonomous system (such
 as router interface failures) and calculates new loop-free routes after a
-period of convergence. This period of convergence is short and involves
-a minimum of routing traffic.
+period of convergence. This period is short and involves only minimal
+routing traffic.
 
-<p>Each router joined in OSPF periodically sends hello messages out
-all its interfaces. This allows neighbors to be discovered dynamically.
-Then the neighbors exchange theirs parts of database. And keep it
-identical flooding updates. Flooding proces is reliable and ensures
-that each routes detects the change.
+<p>Each router participating in OSPF routing periodically sends Hello messages
+to all its interfaces. This allows neighbors to be discovered dynamically.
+Then the neighbors exchange theirs parts of the link state database and keep it
+identical by flooding updates. The flooding process is reliable and ensures
+that each router detects all changes.
 
 <sect1>Configuration
 
@@ -914,11 +918,11 @@ that each routes detects the change.
 
 <code>
 protocol ospf &lt;name&gt; {
-	rfc1583compat bool;
+	rfc1583compat &lt;bool&gt;;
 	area &lt;id&gt; {
 		stub &lt;bool&gt;;
 		tick &lt;num&gt;;
-		interface &lt;interface&gt;
+		interface &lt;interface pattern&gt;
 		{
 			cost &lt;num&gt;;
 			hello &lt;num&gt;;
@@ -939,93 +943,92 @@ protocol ospf &lt;name&gt; {
 
 <descrip>
 	<tag>rfc1583compat <M>bool</M></tag>
-	 This option can disable or enable compatibility of routing table
+	 This option controls compatibility of routing table
 	 calculation with RFC 1583<htmlurl
 	 url="ftp://ftp.rfc-editor.org/in-notes/rfc1583.txt">. Default
 	 value is no.
 	
 	<tag>area <M>id</M></tag>
-	 This specifies area id of configured OSPF area. It can be written
-	 as a number or as an IPv4 number. The most important area is
-	 the backbone (area id 0) to which every other area must be connected.
+	 This defines an OSPF area with given area ID (an integer or an IPv4
+	 address, similarly to a router ID).
+	 The most important area is
+	 the backbone (ID 0) to which every other area must be connected.
 
 	<tag>stub <M>bool</M></tag>
-	 No external routes are flooded into stub area. Default value is no.
+	 No external routes are flooded into stub areas. Default value is no.
 
 	<tag>tick <M>num</M></tag>
-	 The routing table calculation is not processed when any single
-	 change comes. To lower the CPU utilization it's processed late
-	 in periodical interval. The default value is 7.
+	 The routing table calculation is not performed when a single link state
+	 change arrives. To lower the CPU utilization, it's processed later
+	 at periodical intervals of <m/num/ seconds. The default value is 7.
 
-	<tag>interface <M>interface</M></tag>
-	 This mean that specified interface (or interface pattern) belongs
-	 to actual area.
+	<tag>interface <M>pattern</M></tag>
+	 Defines that the specified interfaces belong to the area being defined.
 
 	<tag>cost <M>num</M></tag>
-	 Specifies output cost of interface. Default value is 10.
+	 Specifies output cost (metric) of an interface. Default value is 10.
 
 	<tag>hello <M>num</M></tag>
-	 Specifies interval between sending hello messages. Beware, all
-	 router on the same network has to have the same hello interval.
+	 Specifies interval in seconds between sending of Hello messages. Beware, all
+	 routers on the same network need to have the same hello interval.
 	 Default value is 10.
 
 	<tag>retransmit <M>num</M></tag>
-	 Specifies interval between retransmiting unacknoledged update.
+	 Specifies interval in seconds between retransmissions of unacknoledged updates.
 	 Default value is 5.
 
         <tag>priority <M>num</M></tag>
-	 On every multiple access network (like e.g ethernet) Designed
-	 and Backup Designed router is elected. These routers have some
-	 special functions in flooding process. Higher priority rices
-	 preferences in elections. Routers with priority 0 are not
+	 On every multiple access network (e.g., the Ethernet) Designed Router
+	 and Backup Designed router are elected. These routers have some
+	 special functions in the flooding process. Higher priority increases
+	 preferences in this election. Routers with priority 0 are not
 	 eligible. Default value is 1.
 
 	<tag>wait <M>num</M></tag>
-	 After start, router waits specified interval between starting
+	 After start, router waits for the specified number of seconds between starting
 	 election and building adjacency. Default value is 40.
 	 
 	<tag>dead count <M>num</M></tag>
-	 When router does not receive any message from neighbor in
-	 <m/dead count/*<m/hello/ seconds, it will declare neighbor down.
+	 When the router does not receive any messages from a neighbor in
+	 <m/dead count/*<m/hello/ seconds, it will consider the neighbor down.
 
-	<tag>type <M>broadcast</M></tag>
-	 BIRD detects a type of connected network. However, sometimes is
-	 necessary to change it. On broadcast networks are flooding
-	 and hello messages sent using multicasting. (Single
-	 packet to all neighbors.)
+	<tag>type broadcast</tag>
+	 BIRD detects a type of a connected network automatically, but sometimes it's
+	 convenient to force use of a different type manually.
+	 On broadcast networks, flooding and Hello messages are sent using multicasts (a single packet for all the neighbors).
 
-	<tag>type <M>nonbroadcast</M></tag>
-	 On nonbroadcast network are packets sent to each neighbor
-	 separately because of lack of multicast messages.
+	<tag>type nonbroadcast</tag>
+	 On nonbroadcast networks, the packets are sent to each neighbor
+	 separately because of lack of multicast capabilities.
 
-	<tag>type <M>pointopoint</M></tag>
-	 Pointopoint network connects just 2 routers together. No election
-	 is provided there, this reduces a number of sent messages.
+	<tag>type pointopoint</tag>
+	 Point-to-point networks connect just 2 routers together. No election
+	 is performed there which reduces the number of messages sent.
 
-	<tag>authetication <M>none</M></tag>
-	 No passwords are sent in OSPF's packets. This is default value.
+	<tag>authetication none</tag>
+	 No passwords are sent in OSPF packets. This is the default value.
 
-	<tag>authetication <M>simple</M></tag>
-	 In every packet is sent an 8 bytes long password. Received packets
-	 without this password are ignored. This autentication mechanism is
+	<tag>authetication simple</tag>
+	 Every packet carries 8 bytes of password. Received packets
+	 lacking this password are ignored. This autentication mechanism is
 	 very weak.
 
 	<tag>password <M>text</M></tag>
-	 An 8 bytes long password used for authentication.
+	 An 8-byte password used for authentication.
 
 	<tag>neighbors</tag>
-	 A set of neighbors to which hello messages on nonbroadcast networks
-	 are sent.
+	 A set of neighbors to which Hello messages on nonbroadcast networks
+	 are to be sent.
 </descrip>
 
 <sect1>Attributes
 
-<p>OSPF defines 3 route attributes. Each internal route has a metric. External
-routes uses metric type 1 or metric type 2. Metric type one is comparable
-with internal metric. Metric type 2 is always longer then metric type 1
-or internal metric. Each external route can also carry a tag. Tag is
-32 bits long number and it's used for exporting routes to other protocols
-in link-state it has no funtion.
+<p>OSPF defines three route attributes. Each internal route has a metric. External
+routes use metric type 1 or metric type 2. A metric of type 1 is comparable
+with internal metrics, a metric of type 2 is always longer than any metric of type 1
+or any internal metric. Each external route can also carry a tag which is
+a 32-bit integer which is used when exporting routes to other protocols; otherwise,
+it doesn't affect routing inside the OSPF domain at all.
 
 <sect1>Example