C.A.G is a refrigeration company. This company provides some refrigeration elements all over Europe. They have several employees on site for commercial work, an others outside. It is a middle company with about 150 employees.
Elastix inside an Alcatel OmniPCX Enterprise (OXE) Network with a Codian Bridge.
C.A.G
France
Author: Franck Danard - ECE
This company wants perform video conferences with their employees outside the complex easily. Due to the requirement to be connected at a video conference, every employee had an ISDN access and a video device (Video Phones, Video bridge system).
This company already has implementations with a Codian Bridge and an IPPBX network (Alcatel OXE), all over France (Some nodes in France, and some remotes A.C.T.). They dispose equally a Codian Bridge (ISDN & SIP) and a LAN network with a WAN access. The client has a SIP phone GrandStream GXV 3000 to make some test with the video conference and all the X-Lite extensions.
The client required to be able to make a video conference to the Codian Bridge from anywhere in France and Europe. He also required to be able to make an outgoing call to the Alcatel IPPBX OXE, and to be able to receive incoming calls from the Alcatel IPBX (from internal and an ISDN trunk).
The best system available to complete the requirement is a system based on Asterisk. We choose Elastix as the complementary solution.
The actual amount of concurrent calls between the Elastix, the Codian Bridge and the Alcatel OXE (across the WAN access) is 10. Maybe in the future, more SIP extensions would be added.
The technology used by every employee is an X-Lite – CounterPath softphone. This Softphone is free and provides lots of advantages including a complete list of audio and video codecs, video capability, easy installation process, Multi-OS (Windows, Linux). It’s also easy to use and has a good audio quality.
We used different technologies such as SIP and UA protocol (Alcatel standard).
The SIP technology is employed for the VoIP / ToIP, based on Ethernet OS. The UA technology is from Alcatel and is proprietary, based without IP protocol. These devices are connected on the UAi16 which will be able to receive 16 phones.
In addition, an ISDN trunk is included to make outbound calls to the operator and a SIP Trunk to make any call between the Alcatel OXE and the Elastix server.
Now, we are ready to add our Elastix server into the LAN network. This server is a simple personal computer with 40 GB of Hard-Disk, 1 GB of RAM, an Ethernet device 100 BT, and a CPU of 1.5 GHz.
The client gave us a free IP address for this server. We need a SIP trunk for OXE connection, and a WAN access for any remote user extensions (managed by the client). About OXE, we need to make a T2 trunk with a Qsig GF protocol, all on a SIP gateway. The IPBX Alcatel OXE needs some licenses keys to enable the SIP protocol, the SIP gateway, and the SIP user (Not free).
Apart from this there is nothing in particular about this implementation. The bandwidth is enough qualified for every calls with each codecs (Audio and video) until 10 concurrent's calls. More, if the users not use the video!
The selected bandwidth is enough to make 10 concurrent video calls. The bandwidth will be greater if the call does not use video.
Alcatel OXE can use 3 codecs: G711a, (G711ยต for export series), G729, and G273. For this configuration, it was selected a G711a codec, (the best MOS quality). The OXE accept the ‘canreinvite’ (RTP direct) on the SIP trunk, very useful.
About SIP trunk part Elastix, it's very simple; the configuration is like this in (example #1). For test, no user and password is required. In the future, it will select a user with a secret code, and why not, a md5 authentication.
If you look at the example #1, you could see that the context is 'from-internal'. The trunk needs to use it to select this context to be recognized as an internal call. If the trunk uses another context like ‘from-pstn’ or ‘from-trunk’, every call then will be recognized like an external incoming call. This is very important.
About the dialplan with the Alcatel OXE, it must be common at least with the DID.
The Codian Brige is included like a simple SIP extension with the H263 and H263+ video codec and G711a (alaw) audio codec. Every X-Lite extension should have the same configuration, and same thing about the GrandStream GXV 3000 video phone.
Every SIP remote extensions should have the 'nat=yes' parameter to be able to make incoming calls with each internal phone to the OXE and be able to connect to the Codian Brige. It is important to remember that the router should forward every SIP port and RTP port to the Elastix server. This part is managed by the client.
The investments are not expensive at the Elastix side, but it could be increased by the license keys required by the Alcatel OXE. Every X-lite soft-phone is free. The server hardware is not expensive compared with the capabilities.
Service improvement
Every employee can participate at any video conference. Before the implementation it was difficult, and even impossible with the video and the client should have another video conference system or an ISDN video-phone. Today, with this solution and a WAN access, it's easier.
Every employee can make calls. (There is no need to pay any call to another operator. The outbound call is directly send from the siege).
Every employee can call any UA internal phones. (There is no need to use an operator).
With this configuration, the client:
Can receive incoming calls directly from ISDN with a DID number.
Can connect to the video conference from anywhere.
The implementation it’s easy to use, it can be improved on an already existing IPPBX, and be useful for every employees of the company.
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