This commit was manufactured by cvs2svn to create tag 'v1-0-9'.

git-svn-id: http://svn.digium.com/svn/asterisk/tags/v1-0-9@6013 f38db490-d61c-443f-a65b-d21fe96a405b

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@@ -136,6 +136,67 @@ parameters.  For example, the line "channel => 25-47" creates objects for
 the channels 25 through 47 of the tormenta card, obtaining the settings
 from the variables specified above.
 
+* SPECIAL NOTE ON TIME
+  
+  Those using SIP phones should be aware the Asterisk is sensitive to
+large jumps in time.  Manually changing the system time using date(1)
+(or other similar commands) may cause SIP registrations and other
+internal processes to fail.  If your system cannot keep accurate time
+by itself use NTP (http://www.ntp.org/) to keep the system clock
+synchronized to "real time".  NTP is designed to keep the system clock
+synchronized by speeding up or slowing down the system clock until it
+is synchronized to "real time" rather than by jumping the time and
+causing discontinuities. Most Linux distributions include precompiled
+versions of NTP.  Beware of some time synchronization methods that get
+the correct real time periodically and then manually set the system
+clock.
+
+  Apparent time changes due to daylight savings time are just that,
+apparent.  The use of daylight savings time in a Linux system is
+purely a user interface issue and does not affect the operation of the
+Linux kernel or Asterisk.  The system clock on Linux kernels operates
+on UTC.  UTC does not use daylight savings time.
+   
+  Also note that this issue is separate from the clocking of TDM
+channels, and is known to at least affect SIP registrations.
+
+* FILE DESCRIPTORS
+
+  Depending on the size of your system and your configuration,
+Asterisk can consume a large number of file descriptors.  In UNIX,
+file descriptors are used for more than just files on disk.  File
+descriptors are also used for handling network communication
+(e.g. SIP, IAX2, or H.323 calls) and hardware access (e.g. analog and
+digital trunk hardware).  Asterisk accesses many on-disk files for
+everything from configuration information to voicemail storage.
+
+  Most systems limit the number of file descriptors that Asterisk can
+have open at one time.  This can limit the number of simultaneous
+calls that your system can handle.  For example, if the limit is set
+at 1024 (a common default value) Asterisk can handle approxiately 150
+SIP calls simultaneously.  To change the number of file descriptors
+follow the instructions for your system below:
+
+== PAM-based Linux System ==
+
+  If your system uses PAM (Pluggable Authentication Modules) edit
+/etc/security/limits.conf.  Add these lines to the bottom of the file:
+
+root            soft    nofile          4096
+root            hard    nofile          8196
+asterisk        soft    nofile          4096
+asterisk        hard    nofile          8196
+
+(adjust the numbers to taste).  You may need to reboot the system for
+these changes to take effect.
+
+== Generic UNIX System ==
+
+  If there are no instructions specifically adapted to your system
+above you can try adding the command "ulimit -n 8192" to the script
+that starts Asterisk.
+
+
 * MORE INFORMATION
 
 See the doc directory for more documentation.