Snom 4S Media Server Use and care manual

Administrator‘s
Guide
snom 4S
SIP Proxy/Registrar
Version 2.37

snom technology AG • 3
snom 4S Registrar Proxy Version 2.37 User Manual
© 2003 snom technology Aktiengesellschaft. All Rights Reserved.
This document is supplied by snom technology AG for information purposes only to licensed
users of the snom 4S registrar proxy and is supplied on an “AS IS” basis, that is, without any
warranties whatsoever, express or implied.
Information in this document is subject to change without notice and does not represent any
commitment on the part of snom technology AG. The software described in this document
is furnished under a license agreement and may be used only in accordance with the terms
of that license agreement. It is against the law to copy or use this software except as
specically allowed in the license. No part of this document may be reproduced, republished
or retransmitted in any form or by any means whatsoever, whether electronically or
mechanically, including, but not limited to, by way of photocopying, recording, information
recording or through retrieval systems, without the express written permission of snom
technology AG.
Legal Disclaimer
snom offers the software described in this manual for both open source operating systems
as well as licensed operating systems. Whenever software that has been used under GPL or
LGPL licensing conditions has been used by this product you can download the sources from
www.snom.com/downlad/gpl/snom_ossdk or purchase a disc from snom for a nominal fee
under the ordering code SKU snom-ip-OS-SDK-001.

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Read This First
Before you start using the proxy and continue with the rest of this
manual please read the following important notes.
Upgrades
The 2.3x edition of the proxy uses the same license keys as the
previous versions. However, because of the domain concept, the license
checking algorithm had to be changed and the new proxy now checks
the hostnames directly against the found IP address. Therefore, the list
of hostnames should now include the IP address of the host. If you have
problems with this, please contact mailto:[email protected], please
include the old license information. We will give you a new license key in
this case.
The proxy keeps many of the proven concepts of the previous
versions, however introduces scripting and domains which makes it hard
for the installation process to automatically convert the conguration data
from the 2.2x proxy versions into the new version. Some of the settings
need manual update.
Therefore, if you update the proxy, we ask you to save old
conguration information for later reference. You can do this easily by
storing the web content of the relevant conguration pages to a le.
You can always nd information about the changes at our web
site, http://snom.com/download/proxy-release-notes.pdf.
Additional Information
This manual does not cover all topics that are related to the
usage of the proxy. We keep a list of frequently asked questions (FAQ) on
our website at http://snom.com/faq_en.php for specialized topics such as
remote management via shell script. They also contain topics that affect
other SIP components like the media server or the phones. These FAQ will
be kept up-do-date on a higher frequency than this proxy.
We also keep a list of bug xes in the release notes, which is

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available at the software download site at http://snom.com/down4s_
en.php. Before you make a software update, you make check this
document if the update is necessary or not.

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Table of Contents
Read This First ...........................................................3
Installation ................................................................9
Update to 2.3x from 2.2x............................................................. 9
Choosing Ports ........................................................................... 9
Windows Installation ................................................................. 11
Uninstalling in Windows............................................................................................................................................................ 14
Linux Installation ...................................................................... 14
Manual Starting..................................................................................................................................................................................... 15
Automatic Starting ........................................................................................................................................................................... 15
Software Updates............................................................................................................................................................................... 16
Accessing the web server........................................................... 16
Licensing ................................................................................. 17
DNS Setup............................................................................... 18
DNS Example............................................................................................................................................................................................ 19
General Setup...........................................................21
System Settings ....................................................................... 21
SIP Port............................................................................................................................................................................................................. 21
STUN port...................................................................................................................................................................................................... 21
Log Level ........................................................................................................................................................................................................ 21
Log Filename............................................................................................................................................................................................. 22
Explicit IP address............................................................................................................................................................................. 22
HTTP port....................................................................................................................................................................................................... 22
HTTP User and Password......................................................................................................................................................... 22
Conguration in XML..................................................................................................................................................................... 23
Domains ...................................................................25
Deriving settings ...................................................................... 25
Creating a domain ................................................................... 26
Deleting a domain..................................................................... 26
Edit a domain........................................................................... 27
Going to a domain context ......................................................... 27

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Backup.................................................................................... 27
Server Farm .............................................................29
Shutting servers down............................................................... 29
Number of necessary servers ..................................................... 29
DNS considerations ................................................................... 30
Refresh rate considerations ........................................................ 31
Settings .................................................................................. 31
Domain Settings .......................................................33
HTTP Interface ......................................................................... 33
Conferencing and Call-back ........................................................ 33
Accounts ..................................................................35
Purpose................................................................................... 35
Setting up accounts from the web interface.................................. 36
Uploading user accounts from le .............................................. 36
Storing information .................................................................. 37
Registration .............................................................39
Registration Settings ................................................................. 39
Require Authorization................................................................................................................................................................... 39
Min and Max registration time......................................................................................................................................... 39
Default Q ........................................................................................................................................................................................................ 40
Reject Registrations across NAT................................................................................................................................... 40
Routing ....................................................................41
Domain Administrator Settings ................................................... 41
Protected Destinations................................................................................................................................................................ 41
Sequential Forking Time .......................................................................................................................................................... 42
System Administrator Settings ................................................... 43
Max Forwards........................................................................................................................................................................................... 43
Call Log File ................................................................................................................................................................................................ 43
Tel Domain................................................................................................................................................................................................... 43
ENUM Sufx................................................................................................................................................................................................ 43
NAT Gateway............................................................................................................................................................................................ 43
No Loose Routing ............................................................................................................................................................................... 44
Don’t Always Record-Route................................................................................................................................................. 44
Dial Plan.................................................................................. 45
How it works.............................................................................................................................................................................................. 45

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Example 1: Setting up overlap dialling............................................................................................................... 47
Example 2: North American Dial Plan .................................................................................................................. 47
Example 3: Do not allow cell phone numbers to certain users........................................ 48
Example 4: Using ENUM ............................................................ 49
Error-Information ..................................................................... 49
Message Handling ....................................................51
Store & Forward ....................................................................... 51
Welcome Message..................................................................... 51
Status Reports .........................................................53
Registered Users ...................................................................... 53
Call Logs ................................................................................. 54
Condition for Logging a Call................................................................................................................................................ 54
Call Logs in the Web Interface........................................................................................................................................ 54
Call Attempts............................................................................................................................................................................................ 55
SIP Trace................................................................................. 55
Logs ....................................................................................... 56
Unavailable Hosts ..................................................................... 56
Memory Usage ......................................................................... 57
Billing.......................................................................59
CDR Generation........................................................................ 59
Call Log File Format........................................................................................................................................................................ 59
XML-Based format............................................................................................................................................................................. 60
RADIUS................................................................................... 61
Authentication and Accounting....................................................................................................................................... 61
Setup.................................................................................................................................................................................................................... 61
RADIUS Server....................................................................................................................................................................................... 62
Security ............................................................................................................................................................................................................ 62
Index .....................................................................103

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Installation
Update to 2.3x from 2.2x
Versions 2.3x introduces a domain concept which is not directly
compatible to the 2.2x versions. The conguration information is stored
in a central directory, along with all other conguration information. The
previous versions used a different approach.
All conguration information is now stored in an XML-based
format in the le system. This approach makes it easier to maintain the
software across the various platforms and allows you to use standard
tools to maintain the conguration data e.g. for backup or revision control.
The XML les can be retrieved via the web interface which simplies the
support for the product across the Internet.
Although much of the interface remains the same, the software
update process cannot automatically convert the old conguration
information into the new format. Therefore, it is necessary to enter the
conguration information up again.
In case that you use an extensive dial plan, we recommend taking
a look at the scripting interface as it solves problems with the table based
dial plan. However, for simple installations you can still use the dial plan.
Choosing Ports
The proxy uses a number of ports for its communication to the
outside world. The most important port for installation and conguration
is the http port. You need this port in order to access the proxy with a web
browser.
The default http port number is 80. This is a reasonable choice in
case that you are not running any other http services on that machine or
that users want to access the machine. If you choose another port, users

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always have to specify the complete address including the port number.
Unfortunately, Microsoft Internet Explorer expects the complete address
including the scheme in this case (http://proxy:1234), which makes it
inconvenient to access to proxy. Therefore, if possible you should use
port 80. Otherwise, we recommend linking the proxy with the company
web site, so that users can easily access the proxy with a click and set a
bookmark.
If the port 80 is occupied by other services, you can select any
other port. If the proxy also cannot allocate your specied port, it will
try port 5068 and on. However, you should avoid the situation when the
proxy selects the port.
The SIP port for the proxy should be set 5060. You can specify
also any other port; however some SIP user agents expect the proxy to
use 5060 and you can avoid trouble by using another port.
Figure 1-1: Installation Welcome Screen

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Windows Installation
Important: If you are doing an update, you rst need to stop
and uninstall the old proxy (see below).
After double clicking on the setup executable, the installations
program starts up (see g. 1-1). Press “next” to begin the installation.
At the beginning of the installation the setup program asks you
to accept the license conditions (see g. 1-2). Please read them carefully,
and then select the “accept” button and press “next” to accept the
conditions. If you decline, the installation will be aborted.
After accepting the license agreement, the next screen asks you
to enter your personal information. Enter your name and the name of
organization.
1.
Figure 1-2: Installation License Agreement

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You can then select the location where the proxy’s les will be put.
The installation program proposes a reasonable location but if you want
to you can change it. After this, the installation asks you for the location
where the registration information will be put. This directory needs
write access and will contain the information for registered users. The
installation program proposes a location relative to the proxy installation
directory, but it might be useful to specify a different location for this, e.g.
a temporary directory. It is important that the directory exists; the proxy
will not create this directory.
In the next step you can select the installation type. We
recommend using the “typical” installation.
Before the installation nishes, you need to dene on which ports
the proxy will operate. This is important because otherwise it will be hard
for you to nd the right port.
1.
Figure 1-3: Installation Customer Information

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After nishing the setup wizard, check that the proxy is running.
If you do not want to reboot your system (because it is running other
critical applications), you can also manually start the service in the
services section of the Windows control interface.
Check that the installation has been successful by checking the
Services eld of Windows. Open the services Window and look for “snom
4S SIP Proxy/Registrar”. The status should be “Started”. If this is not the
case you should invoke the proxy by selecting “start”. In this case, we
recommend rebooting the system to make sure that the proxy is running
after the reboot.
After making sure the proxy is running, you should connect to
the proxy to a web browser. In order to do this, you can connect to the
address of the local computer (http://127.0.0.1:8080 if you are running
the web browser on the same machine). It is important that you connect
to the proxy to a web browser, because that is the only way to control the
proxy.
1.
Figure 1-4: Services in Windows

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Uninstalling in Windows
To uninstall the proxy, rst stop it in the services window. Then
go to the Software Window and click on “remove” for snom 4S proxy
Server.
Linux Installation
The software runs under SuSE (7.2 or 8.0) and Red Hat (8.0)
Linux; other Linux versions like mandrake will also be able run the proxy,
but these versions are not explicitly supported in the installation script.
1.
Figure 1-5: Installation Port Denition
Figure 1-6: Software Dialog in Windows

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We strongly recommend using one of the supported Linux distributions in
order to keep the proxy stable.
Manual Starting
If you just want to try the proxy, it should be enough to start the
proxy manually. Load the tarball to a directory of your choice and start the
proxy with the command “proxy”. You can use the command line arguments
shown in the next chapter. You don‘t need to have root permissions to run
the proxy in this mode, normal user rights are enough.
Automatic Starting
If you want the proxy to be started automatically after a reboot,
you need to set up some les as a root. Make sure that you are logged
in as root and go to the directory where you want to put the proxy. This
directory will have subdirectories for the different proxy versions and for
registrations. It typically also contains the conguration information.
su -
cd /usr/local
tar xvfz ~/snom_sip_proxy-i386-linux-2.37.tgz
Go to the directory where you extracted the new version:
cd snom_sip_proxy-i386-linux-2.37
The tarball includes a shell script with the name install.sh which
sets up the necessary les and links for you:
./install.sh
The le /etc/rc.cong (for SuSu Linux) and /etc/init.d/functions
(for RedHat) are appended with the variable “START_SIP_PROXY” and the
SIP_PROXY_OPTS variable is set to a value depending on the html port
that you specify. You can edit the le and modify the value.
The installation script for SuSE will install a command
rcsnomproxy. “rcsnomproxy start” starts the proxy while “rcsnomproxy
stop” terminates the proxy process. For RedHat, you can use the Service
Manager to control the proxy.
After the installation you should see that the proxy is running.
Open a web browser to see if the proxy is up and running. Reboot the
system and check whether the sip proxy was started automatically after
the reboot. You can then continue with the installation using the web
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browser. Stop and restart the proxy with the rcsnomproxy command to
check whether the conguration has been saved.
Software Updates
To update a version, copy the latest tarball into the directory and
run the install script of the new version. It will automatically shut down
the old proxy and run the new one. This takes less than a second and all
registered users will be still registered. However, ongoing calls will not be
billed during this update period.
Accessing the web server
Open a web browser and enter the http address of the proxy.
If the browser is running on the same host as a proxy, you may use
2.
Figure 1-7: Login Dialog

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the address "127.0.0.1". If you did not enter port 80, you also need to
append the port number to that address, separated by a colon. Many web
browsers need to have the resource identier in front of this address like
"http://127.0.0.1:5068". If you did not enter a valid port (for example
because the port is already occupied) the proxy will try ports 5068 and
on. You might have to try these ports in order to get access to the proxy.
In this case you should dene the port number explicitly later in order to
avoid future confusion.
You will then see the login page of the proxy. The default user
name and password are "admin" with no password. Please enter this and
push the login button.
You will see that the proxy opens the session for you. The session
identier is always kept with all the links that you used during your
interaction with the proxy. The session is automatically deleted when you
don‘t use the proxy for more than one hour. To delete the session, click
the logout link.
The proxy offers links in the left frame for easy navigation. There
are different menus for administrator mode, domain administrator mode
and user mode.
Licensing
There are a number of license modes available for the proxy.
When you downloaded the proxy from the Internet, you will probably
have a demonstration license key. This license key is a valid independently
from the host names that you enter. However it will become invalid after
the indicated date. Please notice that it is not possible to overwrite the
demonstration license key with another demonstration license key.
When you buy the proxy from snom, you will receive a license
key. This license key depends on the host names that you enter in the
rst eld. The "Hostnames" eld has a function to uniquely identify this
copy of the snom SIP proxy. Therefore, when requesting the license key
from snom you should use the DNS names of the host which will run
the proxy. You should also include the IP address of this host. Examples
are "proxy.mycompany.com 213.43.34.12" or "sip.mycompany.com
mycompany.net 32.43.12.32". Please always use fully qualied DNS
names including dots. When you are using private addresses, please also
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specify a fully qualied DNS name so that snom can clearly identify the
copy of the SIP proxy.
To see the possible license types please refer to the data sheet.
After entering the license code, you can see the administration menu of
the SIP proxy.
In case you have trouble licensing the proxy, please contact your
reseller and provide the host names that you intend to license the proxy
to.
DNS Setup
After you set up the proxy, you need to make sure it can be
found. Depending on the sophistication of your installation, you need to
set up some DNS entries. This manual does not describe how you change
2.
Figure 1-8: Login Dialog

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the DNS entries; for this purpose, please consult the manual of the DNS
tool that you are using.
As long as you are using plain IP Version 4 addresses, you
don’t need to change anything with DNS. This might be appropriate
in a completely private network with only one proxy server at a xed
address.
SIP uses several DNS levels. The rst level is called NAPTR and
this is a way to determine on a exible way where a service can be found.
ENUM is built upon this level. If you want to locate your proxy using
ENUM, you will probably need the support of additional tools. DNS SRV
is a way to specify addresses for a specic service. Using this level, you
can specify several servers for one address. This enables redundancy and
scalability. DNS SRV is also a way to specify other port numbers than
the default port number for a service. DNS A is the simple DNS address
resolution mechanism we know from the old days that resolves exactly
one address.
We recommend setting up DNS SRV so that you can redirect the
SIP services to a different host than your main server. This way, you can
use the same email addresses for a user as the sip address.
DNS Example
To use the DNS SRV support, you need to dene entries for “_sip._
udp” and “_sip._tcp” for your domain and assign weights and probabilities
to the different hosts that serve these services. A conguration le for
Linux might look like this:
$TTL 1D
anycom.de. IN SOA fox.anycom.de. hostmaster.snom.de. (
2002050111 ; serial
1D ; refresh
2H ; retry
1W ; expiry
1D ) ; minimum
IN NS fox
IN NS ns2.nameserver121.com.
MX 10 mail.anycom.de.
_sip._tcp.anycom.de. IN SRV 0 5 5060 sip-server.anycom.de.
IN SRV 0 1 5060 test.anycom.de.
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IN SRV 1 5 5060 www.anycom.de.
_sip._udp.anycom.de. IN SRV 0 5 5060 sip-server.anycom.de.
IN SRV 0 1 5060 test.anycom.de.
IN SRV 1 5 5060 www.anycom.de.
localhost IN A 127.0.0.1
ns IN A 232.145.142.95
anycom.de. IN A 232.145.142.95
test IN A 232.145.142.95
www IN A 232.145.142.96
sip-server IN A 232.145.142.97
In this example, there are three choices for accessing the proxies
for anycom.de. The rst two, (sip-server.anycom.de and test.anycom.de)
have the weight 0, and as long as one of them is up they will be contacted.
Only if both of them are down, will the service go to www.anycom.de. The
probability of contacting sip-server is 5/6, the probability of contacting
1/6, as the preference sum is 6. That means that most of the load goes
to sip-server.
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