Changeset 11101

Timestamp:

05/27/2008 07:02:55 PM (6 months ago)

Author:

dave

Message:

cosmetic changes

Files:

• dotorg/trunk/html/beps/bep_0022.rst (modified) (8 diffs)

dotorg/trunk/html/beps/bep_0022.rst

@@ -29 +29 @@
 those that share the access network.  When subsequent peers transfer
 from their ISP's cache, the ISP experiences less transit traffic.
+
+The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
+NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and
+"OPTIONAL" in this document are to be interpreted as described in
+IETF RFC 2119 [#RFC-2119]_.
  
 
@@ -127 +132 @@
 matches.
 
-We propose an alternative that avoids wildcards and has the advantage
-that it allows suborganizations to override the SRV records provided
-by parent organizations: the peer starts by querying using its
-fully-qualified domain name returned from the reverse DNS lookup, and
-if this fails then it queries again after removing the most specific
-(leftmost) label in the domain name.  For example, if no SRV records
-are returned when querying for
+We propose an alternative that avoids wildcards and allows
+suborganizations to override SRV records provided by parent
+organizations: the peer starts by querying using its fully-qualified
+domain name returned from the reverse DNS lookup, and if this fails
+then it queries again after removing the most specific (leftmost)
+label in the domain name.  For example, if no SRV records are returned
+when querying for
 
 ::
@@ -151 +156 @@
   _bittorrent-tracker.pltn13.pacbell.net
 
-The search removes one domain at a time terminating when one or more
+The search removes one label at a time terminating when one or more
 resource records are found or before querying the root domain or
 top-level domains that are not ccTLDs, e.g., .com, .org, .net. We
-avoid querying the root or global top-level domains given the low
-likelihood that caches would be defined globally, and thus clients
-would unnecessarily burden the root domain name servers with queries
+avoid querying the root or top-level domains given the low likelihood
+that caches would be defined globally, and thus clients would
+unnecessarily burden the root domain name servers with queries
 generating negative results. We considered stopping before querying
 country-level domains, but a country providing public infrastructure
@@ -174 +179 @@
 address*.
 
-When finding a cache, the BitTorrent client must use its host's
-external IP address.  A BitTorrent client can obtain its host's
-external IP either from the *external ip* key returned from a tracker
-implementing BEP 24 [#BEP-24]_ or from peers using the *yourip*
-extension defined for the *Extension Protocol* proposed in [#BEP-10]_.
-
+The BitTorrent client must use its host's external IP address.  A
+BitTorrent client MAY obtain its host's external IP either from the
+*external ip* key returned from a tracker implementing BEP 24
+[#BEP-24]_ or from peers implementing the *yourip* extension defined
+for the *Extension Protocol* proposed in [#BEP-10]_.
 
 Example
 =======
 
-In our example, we used AT&T's PacBell network.  AT&T could implement
+In our example, we use AT&T's PacBell network.  AT&T could implement
 cache discovery by adding the following lines to the zone file for
 pacbell.net,
@@ -195 +199 @@
 Now when a client performs cache discovery, it performs three DNS
 queries removing labels before reaching the domain name pacbell.net,
-at which point the SRV record would be returned and the client would
-then query tracker.pacbell.net to obtain caches.
+at which point the SRV record is returned and the client queries
+tracker.pacbell.net to obtain the domain names of caches.
 
 In Python, the cache tracker's port and domain can be obtained using
@@ -208 +212 @@
   names = name.split('.')
   while names and names[0] not in tlds:
-     name = "_bittorrent._tcp." + ".".join(names)
+     name = "_bittorrent-tracker._tcp." + ".".join(names)
      req = DNS.Request( name=name, qtype="SRV", protocol="udp")
      response = req.req()
@@ -227 +231 @@
   ;; flags: qr aa rd ra; Ques: 1, Ans: 1, Auth: 2, Addit: 3
   ;; QUESTIONS:
-  ;;      _bittorrent._tcp.pacbell.net, type = SRV, class = IN
+  ;;      _bittorrent-tracker._tcp.pacbell.net, type = SRV, class = IN
   
   ;; ANSWERS:
-  _bittorrent._tcp.pacbell.net    600    SRV     (5, 0, 6969, 'cache.pacbell.net')
+  _bittorrent-tracker._tcp.pacbell.net    600    SRV     (5, 0, 6969, 'cache.pacbell.net')
   
   ;; AUTHORITY RECORDS:
@@ -255 +259 @@
 ==========
 
-.. [#BEP-3] BEP_0003. The BitTorrent Protocol Specification, Cohen
-   (http://www.bittorrent.org/beps/bep_0003.html)
-
-.. [#BEP-10] BEP_0010.  Extension Protocol. Norberg, Strigeus, Hazel
-   (http://www.bittorrent.org/beps/bep_0010.html)
-
-.. [#BEP-24] BEP_0024.  Tracker Returns External IP.  Harrison
-   (http://www.bittorrent.org/beps/bep_0024.html)
+.. [#BEP-3] BEP_0003. The BitTorrent Protocol Specification, Cohen.
+   http://www.bittorrent.org/beps/bep_0003.html
+
+.. [#BEP-10] BEP_0010.  Extension Protocol. Norberg, Strigeus, Hazel.
+   http://www.bittorrent.org/beps/bep_0010.html
+
+.. [#BEP-24] BEP_0024.  Tracker Returns External IP.  Harrison.
+   http://www.bittorrent.org/beps/bep_0024.html
 
 .. [#RFC-1034] RFC-1034.  DOMAIN NAMES - CONCEPTS AND FACILITIES. Mockapetris,
-   November 1987. (http://tools.ietf.org/html/rfc1034)
+   November 1987. http://tools.ietf.org/html/rfc1034
+
+.. [#RFC-2119] RFC-2119. http://www.ietf.org/rfc/rfc2119.txt
 
 .. [#RFC-2782] RFC-2782.  A DNS RR for specifying the location of services (DNS
    SRV). Gulbrandsen, Vixie, Esibov. February 2000. 
-   (http://tools.ietf.org/html/rfc2782)
-
-.. [#RFC-4592] RFC-4592. The Role of Wildcards in the Domain Name System. Lewis
-   (http://www.faqs.org/rfcs/rfc4592.html)
+   http://tools.ietf.org/html/rfc2782
+
+.. [#RFC-4592] RFC-4592. The Role of Wildcards in the Domain Name
+   System. Lewis.  http://www.faqs.org/rfcs/rfc4592.html