34
www.xorcom.com The Only Commercially- Supported Complete Failover Solution for Asterisk Asterisk is a registered trademark of Digium, Inc. TwinStar – Winner of IT Expo “Best of Show”
www.xorcom.com
The Only Commercially-
Supported Complete Failover
Solution for Asterisk
Asterisk is a registered trademark of Digium, Inc.
TwinStar – Winner of IT Expo “Best of Show”
www.xorcom.com
Agenda
Downtime is the Enemy
The Key is in the Architecture
Complete Failover Solution
Additional Reliability Tools
Review of Key Points
Questions & Answers
www.xorcom.com
THIS WEBINAR IS BASED ON A
SINGLE, SIMPLE PREMISE…
You
!!
www.xorcom.com
iPBX is great-but what about reliability?!
www.xorcom.com
Traditional iPBX Redundancy
Characteristics
Duplicate servers
Server failure necessitates
manual intervention
• Start backup
• Re-attach cables to telephony modules
Drawbacks
Expensive
Time-consuming
• May take hours or even days to fix
www.xorcom.com
Introduction to Xorcom
Established in 2004
Flexible and modular telephony interface
solutions based on XPP™ technology (USB2)
Xorcom drivers: standard component in
Asterisk since v. 1.2.4 (Feb ‘06)
Worldwide distribution
& OEM channels
Distributor OEM
New Standard for Asterisk Connectivity
www.xorcom.com
XPP: Unique Platform for Telephony
High speed 480 Mbit/s USB2 connectivity
Supports very high densities
Theoretical uncompressed voice:
2,400 calls/USB
Full support for fax and modems
Modular and scalable
Additional ports are ‘hot pluggable’
Simple integration and maintenance
www.xorcom.com
Astribank Overview
Direct USB connection to Asterisk server
Drivers are native in Asterisk
Auto detection of analog/digital ports as
Zaptel/DAHDI devices
Full telephony connectivity:
FXS, FXO, PRI (E1/T1), T1 CAS, E1/R2, BRI ISDN
All units are “TwinStar™-ready”
* Astribank
USB
www.xorcom.com
COMPLETE FAILOVER SOLUTION
TwinStar – Winner of IT Expo “Best of Show”
www.xorcom.com
Hot Failover – Xorcom Approach
Provides full redundancy for a complete PBX
system by avoiding “single point of failure”
Auto detection of server failure
and instant switch to backup server
Re-establishes communication for: IP telephones
FXO circuits: standard analog phone lines
FXS circuits: analog telephones and devices, such as fax machines
Digital trunks: E1/T1 PRI, E1 R2, T1 CAS, BRI ISDN
SIP trunks
Digital (ISDN) phones
www.xorcom.com
Components
Duplicate synchronized servers
redundant power
External telephony modules
housed in USB-connected Astribank
Firmware-based switching mechanism that is
not network-dependent
www.xorcom.com
Initial Setup: Identical Servers
Two Xorcom servers + dual-USB Astribank
PSTN
USB USB
Astribank (front panel) telephony interfaces
Xorcom server (backup)
Xorcom server (primary)
Analog Phones
IP Phones
LAN/WAN
www.xorcom.com
Standard Operation: Primary Active
Dual USB ports; Firmware monitoring/switching
IP Phones
PSTN
USB USB
Astribank (rear panel) telephony interfaces
Xorcom server (backup)
Xorcom server (primary)
Analog Phones
LAN/WAN
www.xorcom.com
IP Phones
Analog Phones
If the Primary Server Fails…
PSTN
USB USB
Astribank (rear panel) telephony interfaces
Xorcom server (backup)
Xorcom server (primary)
LAN/WAN
Server
Failure
www.xorcom.com
Analog Phones
IP Phones
…the Backup Server is Activated
PSTN
USB USB
Astribank (rear panel) telephony interfaces
Xorcom server (backup)
Xorcom server (primary)
LAN/WAN
Switch
Changes to
Backup Server
Backup Server
assumes Primary
Server IP Address
www.xorcom.com
Asterisk High Availability Cluster
Two servers comprise the cluster
Each has a private IP address
Server management and configuration
replication performed via IP network
VoIP PBX extensions use special public/cluster
IP address to communicate with PBX cluster
In case primary server fails, the cluster IP
address is automatically activated on backup
IP phones continue to use same PBX IP address
www.xorcom.com
DRBD
DRBD=Distributed Replication Block Device
used to replicate server configuration files
All files to be replicated need to be allocated
in DRBD partition
Asterisk configuration files
MySQL database
Web server
DRBD is mounted on the primary server only,
to avoid simultaneous modification of files
www.xorcom.com
High Availability Software
Xorcom uses USB Watchdog protocol
Detects server failure
Forces backup to take charge
Monitors:
voltage availability on each Astribank USB port
continuity of communication between
Astribank and DAHDI driver
www.xorcom.com
In Case of Server Failure…
Astribank deactivates primary server USB port
and activates backup server USB port
Plug-and-Play event launched on backup, calls
scripts to check that all devices have switched
Additional script:
registers and configures Astribank channels on DAHDI
mounts DRBD partition to enable Asterisk and MySQL
activates shared IP
starts MySQL, Asterisk and Apache services
www.xorcom.com
Which Failures are Caught?
TwinStar monitors voltage of the active USB port
and communication with DAHDI driver
Switchover to backup server will occur if:
The server is switched off (no power)
The server crashes
The Astribank driver stops working
• Linux kernel crash
• Driver unloaded
The USB cable is disconnected
Switchover can be customized to use Monit or
Linux Heart Beat to catch other failures
www.xorcom.com
Additional Information
Xorcom provides pre-configured synchronized
TwinStar-ready XR2000 and XR3000 appliances
Xorcom does not provide tech support for:
DRBD
any server monitoring software
hardware packages on third party hardware
Soon-to-be-Published: Guide for configuring
“plain vanilla” Elastix for TwinStar-supported
Astribank cluster
www.xorcom.com
Notes for Non-Xorcom Servers
Need DAHDI 2.2 or higher (no Zaptel)
PBXs must be identical in configuration and
capabilities, synchronized continuously in
real-time
Installing TwinStar Astribanks as part of a
solution based on non-Xorcom IP-PBX
does not provide an out-of-the-box high-
availability solution for IP telephony
Consult “How it Works” document for tips
www.xorcom.com
Support for Non-Xorcom Servers
Xorcom supports only USB switching between
primary and backup
Xorcom is not responsible for the correct
operation of the synchronization, IP telephony
high-availability, and other features that are
not directly related to the Astribank operation
Xorcom is not obligated to instruct the
integrator on how to build such a system
www.xorcom.com
Additional Tools
Telephony interface power supply redundancy
Load balanced power
Redundancy
Notifications
Internal hardware redundancy
RAID1
External backup and restore
Fan redundancy
Smart fan control
www.xorcom.com
Review of Key Points
TwinStar is the only commercially-supported
hot fail-over solution for Asterisk-based PBX
Re-establishes communication for: IP telephones
FXO circuits: standard analog phone lines
FXS circuits: analog telephones and devices, such as fax machines
Digital trunks: E1/T1 PRI, E1 R2, T1 CAS, BRI ISDN
SIP trunks
Digital (ISDN) phones
No manual intervention required!!
www.xorcom.com
Questions?
You don’t know what you don’t know
until someone else asks the question…
