TENDENCIAS DEL MERCADO DE COMUNICACIONES 4.1 Introducción
4.11 Diferencias entre el TDM y el DWDM 1 El Legado de la Red de Voz
In the event that you are forced to rebuild the master server and you do not have a recent configuration backup, the quickest way to achieve service continuity quickly and efficiently is to rebuild the master server and re- synchronise it with the distributed system. However, in this case, the newly rebuilt master system’s TLS/SSL certificate information will not match that of the distributed system. Ordinarily, a configuration backup would contain the previous system’s certificate information, but since a backup does not exist in this scenario you will have to manually synchronise the distributed system with the newly rebuilt master by 1) creating a new secondary server profile on the master server; and 2) running through some setup screens on the distributed server.
Note: To avoid DNS and connectivity issues, ensure that both the master and the distributed system are configured with the same LAN settings as before. During the course of this solution we will perform the following tasks:
Create an install disk or USB thumb drive by downloading the SCS software from the Avaya website.
Configure the master server’s boot sequence to ensure that it is capable of booting from the install source.
Configure the master server.
License the master server.
Create a secondary server (redundant server) profile on the master server.
Run ‘sipxecs-setup’ on the secondary server to synchronise with the master.
Send the secondary server profile from the master to the secondary server.
Creating an SCS Installation Build
Before you can configure your SCS server you will need to download and install the SCS software. You will need:
Internet access
Writable DVD/USB thumb drive
DVD burning software capable of creating a bootable DVD from the ISO image – for example Infra Recorder.
Downloading the SCS ISO File
The SCS software is contained in an ISO file, which can be obtained from the Avaya website at http://support.avaya.com. Once downloaded, the ISO file should be burnt to a DVD using a DVD burning package that is capable of creating bootable discs, or written to a bootable USB thumb drive.
Burning the ISO File to DVD
Once you have downloaded the ISO file to a suitable location, you must burn it to a DVD. The DVD will then be used to format the server and install the SCS software. For this reason, it is not enough to simply copy the file to a DVD. The file must be burnt to the DVD and the DVD must be made bootable using a disc burning application – such as Infra Recorder.
Note: Alternatively, you can copy the SCS installation file to a USB drive and boot from that. See ‘Creating a Bootable USB Image’.
In order to install the SCS software you might need to configure the boot settings so that the server reads the CD drive at power up. This is achieved in the following way:
Note: If your server already boots from the CD drive, simply place the installation DVD in the CD tray, close it and reboot the system.
1. Press the Power button to switch the server on.
2. As soon as the blue Dell screen is displayed, press F2 to enter the System Configuration menu.
3. Using the Down cursor key, navigate to the Boot Sequence menu on the left-hand side of the screen.
4. Press Enter to move the menu highlight to the Boot Sequence pane. 5. Using the Up and Down arrows, move the green highlight strip so that
it is resting over Onboard or USB CD-ROM Drive.
6. Use U to move it to the top of the list (if the CD-ROM drive is already at the top of the list ignore this step).
7. Press the Enter key.
8. Open the CD-ROM tray and insert the SCS installation DVD. 9. Close the tray.
10. Press the ESC key to exit System Configuration.
11. Use the Left and Right cursor keys to navigate to Save/Exit. 12. Press the Enter key.
The server will reboot from the DVD and automatically launch the format utility. When the Software Communication System screen is displayed, press the Enter key to confirm that you would like to format the hard drive and install the SCS software.
The format and installation process takes approximately 10 minutes, when it is complete the CD tray will eject and the system will reboot to the login screen, from where you can begin the installation process. Continue to ‘Configuring the SCS Master Server’ for guidance on configuring the server.
Creating a Bootable USB Image
Instead of creating a bootable installation DVD you could instead create a bootable USB image. This will involve:
Writing the SCS ISO image to a ‘bootable’ USB thumb drive using an application called ISO2USB, which can be obtained at http://iso2usb.sourceforge.net
Re-ordering the boot sequence of the Dell server.
Note: The USB thumb drive must have a capacity of 1GB or more. To create a bootable USB drive:
1. Insert a USB thumb drive (ensure that you this is a drive that has no important data on it).
2. Download ISO2USB.
3. The package downloads as a ZIP file. Extract the contents and then double-click on iso2usb.exe to launch the application.
4. Ensure that the Diskimage radio button is selected and that ISO is selected in the top drop-down menu.
6. Select the USB drive from the Drive drop-down menu at the bottom of the window and then click OK.
7. The image is written to the USB drive.
8. When copying is complete, click the Exit button.
You have now created a bootable SCS installation USB drive. Next re-order the boot sequence on the server.
In order to install the SCS software you will need to configure the boot settings so that the server reads the USB drive at power up. This is achieved in the following way:
1. Press the Power button to switch the server on.
2. As soon as the blue Dell screen is displayed, press F2 to enter the System Configuration menu.
3. Using the Down cursor key, navigate to the Boot Sequence menu on the left-hand side of the screen.
4. Press Enter to move the menu highlight to the Boot Sequence pane. 5. Using the Up and Down arrows, move the green highlight strip so that
it is resting over USB Device.
6. Use U to move it to the top of the list
a. On some servers it may be necessary to ‘enable’ the USB device as a boot option. Press the Space bar if USB Device does not have a priority number next to it. A ‘1’ should appear
7. Press the Enter key.
8. Insert the USB thumb drive
9. Press the ESC key to exit System Configuration.
10. Use the Left and Right cursor keys to navigate to Save/Exit. 11. Press the Enter key.
The server will reboot from the USB drive.
When the red Avaya screen is displayed press Enter.
A ‘kickstart’ error will be displayed, this is normal. Simply use the down cursor key on your keyboard to highlight the OK button and press Enter to launch the format utility. When formatting is complete the SCS software will be copied to the server’s hard drive.
The format and installation process takes approximately 5 minutes, when it is complete the system will announce a reboot – Ensure that the USB drive is removed from the USB port before the reboot begins otherwise the system will reboot from the thumb drive again. If you are unable to remove the USB thumb device before the system reboots, wait for the red Avaya
screen to appear, remove the thumb drive and then press CTRL-ALT-DEL to reboot the server.
The system will boot to a login screen.
Configuring the SCS Master Server
Once installation is complete you will be presented with a login screen.
1. To begin the setup process, enter the following username and password to access the configuration utility:
Localhost Login: root
Password: setup
If at any time during the setup process you make an error, reboot the server and log in using the same username and password. At the command prompt type sipxecs-setup-system and press Enter to reload the configuration utility from the start.
Note: The SCS domain cannot be changed by running sipxecs-setup- system. The only way to reconfigure the domain is to access the Domain facility from the administrator GUI.
2. When the configuration utility has finished loading, highlight the Start button and press Enter.
3. Enter the Admin Password twice. This is the password that engineers and administrators will enter to gain access to the SCS server locally via the Linux operating system (where you are now). Highlight the OK button and press Enter when you are ready to continue.
a. Hostname – This is the fully qualified domain name (FQDN) of the SCS server as defined in the DNS records.
b. IP – The IP address that has been assigned for use with the SCS. Again, this must be consistent with the address defined in the DNS settings.
c. Netmask – The network’s subnet mask.
d. Gateway Address – The address of the default router providing access to the Internet.
If you are unsure of any of these settings, see the network administrator.
5. The installation wizard will now query whether or not you have DNS configured on the network. The SCS can be configured to function as a DNS server on the network if you do not have DNS or are unable to configure the required records. To enable the SCS onboard DNS, select No xxx.xxx.xxx should be my DNS server.
Note: If the DNS service is enabled on the first server it will replicate on the secondary server automatically.
Note: The onboard DNS will create all necessary records required by the SCS in order for it to function correctly.
Note: If you elect to enable the SCS’s onboard DNS the next screen will offer you the opportunity to define upstream DNS servers if you wish. If the network utilizes Intranet DNS or DNS from an IP service provider then these server addresses can be entered on the next screen. Note that this is an optional configuration step and the fields can be left blank if required, however without these addresses, name and address resolution may prove difficult since the SCS will not be able to resolve all DNS queries.
If you already have DNS configured for the SCS select Yes xxx.xxx.xxx should not be my DNS server. Note that in this instance the next screen will ask you to configure the address of a primary and secondary DNS server.
6. Select a region or country to set the time zone in which the SCS is situated – if you pick a region, such as ‘Europe’, you will be prompted to then define an area within that region, for example, ‘London’.
7. The system will now search for NTP servers in order to set system time. By default the SCS is programmed to attempt a connection to a series of Internet-based time servers. If it cannot connect to any of these servers you will be asked to either: 1) move on with the current time server configuration, in which case you will have to set the time manually - see Step 7b; 2) configure the address of a different time server. If the SCS successfully gathers NTP data the following message will be displayed:
Note: The NTP server search can take a while. Do not power off or disconnect the SCS during this process, even if it seems that nothing is happening.
Press Enter and continue to Step 8 if you see this message.
If you see the message below regarding NTP servers continue to Step 7a.
a. You now have the choice of configuring a different set of NTP servers or continuing with the default settings and configuring the time manually on the next screen.
i. To set new NTP servers, highlight Reconfigure servers and press the Enter key.
ii. Enter the new NTP addresses and then highlight the OK button and press Enter.
iii. The SCS will attempt to connect to the defined NTP servers.
iv. When a connection is successful press Enter to clear the confirmation screen and then continue to Step 8.
b. Instead of configuring alternative NTP servers you can set the time manually.
i. Highlight Continue with these servers and press Enter. ii. To set the time, use the left and right cursor keys to
move between the fields and the up and down cursor keys to adjust each value. The time should be set in 24- hour format. Highlight the OK button and press Enter to continue.
iii. Continue to Step 8.
8. The SCS can provide a DHCP service in order to provide devices joining the network with IP addresses. To enable the DHCP service select No xxx.xxx.xxx should be my DHCP server.
Note: If a DHCP service is already active on the network do not enable the onboard DHCP service since this will cause a conflict.
9. You now need to configure some settings that will define this server as your primary SIP server. First, define the server as your ‘First Server’. Highlight First Server and press the Enter key.
Next set the SIP Domain. Knowledge of your network configuration is vital at this stage. Because you are dealing with an HA configuration, all required DNS SRV records should already be in place, the SIP domain should simply be entered as the domain name: e.g.,
scsdomain.com (the domain name must be the same on the previous build, otherwise the archive restore will fail). In an HA scenario the SIP domain is never entered as a fully qualified domain name (FQDN). By default the wizard will enter the domain name in the correct format. Note: If you elected to enable the SCS’s own DNS then all required SRV records will be generated automatically, you should therefore leave the SIP domain as the default entry and press the OK button to continue.
In the example illustrated below the SIP domain has already been entered as iteluk.com by the wizard, this is fine because in this instance DNS SRV records are in use on the network.
Highlight the OK button and press the Enter key when you are ready to continue.
10. Configuration of the SCS server is now complete. Highlight the Reboot button and press the Enter key to restart the server.
When the server has restarted, administration of the system can be carried out via the web-browser interface, which can be accessed from a remote workstation/laptop by navigating to the server’s address or host and domain name in a web browser.
Licensing the System
Now that the Master server is installed and configured you will need to licence it before you can commence creating/restoring user and device profiles.
1. Place the mouse pointer over the System menu and select Licensing.
2. To apply your license file, click the Choose file / Browse button and browse to the location of the file. When you have selected a file, click the Apply button.
3. The license file will be applied to the SCS system, enabling the configuration of users based on the number of users purchased.
Once the system is licensed you can commence configuring user accounts and device profiles. In short, you can now bring the system back to full operating condition.
Creating the Secondary Server Profile
With the SCS fully configured and operating you can now reconfigure the secondary HA server to ensure call continuity in the event of future system failure. The existing secondary server configuration will need to be replaced because its TLS/SSL certificate no longer matches that of the primary after the re-installation.
Before you attempt to configure the second server, create a profile on the master, or Primary SIP Server:
1. Open the System menu and select Servers.
3. Enter the following details:
a. Hostname – The hostname that will be applied to the redundant server when you configure it later. This must be consistent with any DNS entries that exist for this server. For help configuring DNS records for use with HA scenarios see the ‘Configuring DNS and DHCP for Windows Server 2003’ guide.
Note: Enter exactly the same details as those that were applied to the original secondary server profile.
b. IP Address – The IP address reserved for the new server. c. Description – Enter a brief description of the server.
d. Password – The SCS will automatically populate this field, but you may wish to enter something easier to remember because this password will be required later when you configure the secondary server. Ensure that you make a note of the password and keep it to hand for later in the process.
e. Branch – Select a branch if the secondary server should route calls through a specific gateway location.
4. Click OK.
5. The new server profile is listed along with the primary. Note that the Description field aids you in identifying one server from another.
Note: At this stage the SCS will request that the Call Detail Records (CDR) service is restarted. Other services will require restarting at a later stage. You can either restart the CDR service now or restart it with the other services later.
You now need to synchronise the master server and secondary servers.
Synchronising the Servers
To synchronise the master server with the secondary server, log in locally or remotely (Putty can be used to access the server remotely using SSH) to the secondary server and, at the prompt, type the following command:
sipxecs-setup
The setup utility will load, configure the settings as follows: 1. Press the Enter key to clear the introductory screen.
2. Select Adding a server and press the Enter key.
3. The next screen acts purely as a reminder, pointing out that before you configure the next settings you must first create a profile in the primary server’s GUI. If you have already created the profile press the Enter key. If you have not yet created a profile for the secondary server ensure that you do before continuing.