Performance of 8E1s Sangoma Netborder Express Gateway

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Abstract:

Sangoma's NetBorder Express is a complete SIP-compliant VoIP to TDM Media Gateway solution that is user friendly and works under Windows operating system . Product consist of Sangoma A10(1/2/4/8) cards (max 32xE1) and dedicated software+drivers. In the article we present results of performance test of this product (8xE1 setup) with FreeSWITCH as a SIP terminating PBX. Tests took place in VoiceWorks laboratory.

Goals:

Test CPU and RAM memory usage in two scenarios :
1 machine - FreeSWITCH and Netborder Express Gateway on the same server,
2 machines - Netborder on Windows machine and FreeSWITCH on Centos Linux

Purpose of this test is to measure performance of the latest Sangoma's product under Windows platform.

Lab Setup :

Hardware
- HP DX2400, Intel Core 2 Quad CPU Q9300 (4x2,5 GHz), 2 GB RAM, 250 GB SATA HDD (Windows)
- noname Intel Xeon 2x2 GHz, 2 GB RAM, 2x110 HDD (Centos Linux)
- Sangoma A108D PCI-e cards, 8 E1 port PSTN cards with HW Echo Cancellation
- 2 x Patton 4960 Gateways (4xE1 each)
- Netborder Express Gateway Card

Sofware
- Windows XP Professional Service Pack 3
- Netborder Express Gateway v 1.6.1
- Sangoma Windows Driver 6.0.5.8
- CentOS 5.2
- FreeSWITCH version 1.0.trunk

Fig. 1 - Netboard test setup schema 1 (centralized)

Fig. 2 - Netboard test setup schema (distributed)

Methodology:

Call scenarios for both setups are the same. We start with empty system and add a new call every 3 seconds untill all chanells are occupied. Then during the period of 5 minutes we drop a random call (every 375 ms) and than replace it with the a new one. Below there is the description of a single call flow:
G.711 SIP call is originated from FreeSWITCH to Sangoma's Netborder Express,
Netbord forwards the call to Patton,
Patton loops the call back to Netboard,
Netbord forwards the call back to FreeSWITCH,
FreeSWITCH answers the call and exectues "Echo" application.
Basically every call occupies 2 time slots.
During the tests we monitor CPU utilization (Total and for every Core), memory usage and HD activity. All the parameters on Windows machine are monitored by build in Performance Monitor. To achieve maximum performance we are disabling all debugs on the Netboard machine.
Patton boxes are also used to check if Sangoma's new products is fully compliant with Euro-ISDN standards.

Configuration:

FreeSWITCH config files:
default.xml (dialplan)
sofia.conf.xml
switch.conf.xml
Netboard Express Gateway config files:
routing-rules.xml

Results:

Fig. 3 - CPU Usage (centralized setup)

Fig. 4 - CPU Usage (distributed setup)

System Setup	RAM Used - Idle state (MB)	RAM Used - Full load state (MB)
Centralized	79	183
Distributed	61	100

Fig. 5 - Memory Usage (distributed setup)

Conclusions:

Tests showed that there is a lot of spare resources for increasing capacity of the system or building complex logic when FreeSWITCH is running under Windows even on everyday desktop computer. Both setups are able to easily handle 8E1s and uses less than 1/4 of the CPU. Simple extrapolation confirms that distributed setup could handle at least 32xE1 on a single machine. CPU load is evenly distributed between cores which guarantees optimal resources usage.
This lab setup also hits at solution for all Open-Source integrators that are faced with obstacles like Windows environment or strict ISDN compliance requirements for their installs.
Sangoma's Netborder Express comes with certification from huge number of vendors opening doors to every possible tender. When coupled with FreeSwitch, the ultimate Open-Source telephony integration tool, running along on the same Windows machine one gets an unbeatable combo in the market segment previously reserved only for selected players.