Preface

“Simplicity carried to an extreme, becomes elegance.” - LanScape Philosophy

Thank you for purchasing LanScape telephony application software. This edition of LanScape’s VOIP Media Proxy® is designed for the Microsoft Windows family of operating systems. The LanScape VOIP Media Proxy® is designed to work seamlessly and with the LanScape Centrex Proxy Server® (SIP proxy). The LanScape Centrex Proxy Server® is used to handle all SIP session traffic and one or more LanScape VOIP Media Proxy® servers are used to proxy the media streams associated with your network phone calls. The LanScape VOIP Media Proxy® technology is completely scalable and load balancing so as your VOIP network system grows, so can your media proxying capacity. When you need additional media proxy support, simply add another LanScape VOIP Media Proxy® to your deployment.

We are extremely pleased to have an opportunity to offer you this feature rich, network based telephony technology to you. We here at LanScape know how difficult it is to get your VOIP network up and running without errors. We have been there, we now. We have performed research that has showed us what is required to overcome today’s hostile network environments and VOIP network hurdles. We have made our best effort to translate this knowledge into our VOIP products. Our single greatest hope is that you discover this incredible technology and harness it for your own benefit.

Voice over IP (VOIP) is truly an incredible development in current network application technology. By structuring and deploying your own Voice over IP solutions, you take control of your communications destiny. You no longer have to bear the expensive cost associated with interconnecting disjoint office facilities using dedicated or leased line telco infrastructures. Initiating and receiving network based phone calls to/from domestic and international locations is available to you right now. You have the incredible ability to use your private intranet and the public internet to communicate in ways you never thought possible. The LanScape VOIP Media Proxy® is designed to be use with the LanScape Centrex Proxy Server® and is meant to be deployed in hostile network environments that are to be used for Voice over IP communications. By deploying LanScape session and media proxy solutions, you will be able to spend your time using your VOIP network instead of trying to figure out why your VOIP network isn’t working.
 

Voice over IP as a technology is simple to understand and simple to apply to real world situations – if you have the right tools. In theory, call endpoints connect to each other and media (audio/video) stream between them. However, we must inform you that today’s network environments post incredible barriers to achieving robust, scalable and useable peer-to-peer VOIP networks. The most important barrier that must be overcome is related to the hostile nature of today’s networks associated with peer-to-peer VOIP communications. You may be asking: What causes a network to be hostile to Voice over IP? The answer is network address translation, port translation and firewalls.

 

Network Address Translation and Port Translation:

Network address translation (NAT) has many uses and is deployed in network environments for many reasons. NAT is primarily used in hardware and software routers.
 

NAT is simple to understand if you know the basics of how TCP/IP and UDP/IP traffic flows over a network. In short, NAT alters the IP address information associated with each data packet that travels through the NAT device (router). Another form of translation is also possible – port translation. Port translation is sometimes referred to as Port Address Translation (PAT) or other similar terms. Port address translation alters the port information associated with each data packet that travels through the network. PAT is typically used for network security reasons. The introduction of NAT/PAT into a network environment causes the network to be hostile to all peer-to-peer technologies, VOIP is just one of those technologies. Another idiosyncrasy of NAT is that hardware and software routers that utilize NAT do not function the same. Most often, routers that utilize NAT have their NAT algorithms implemented differently, which results in different router behaviors even for the same category of router (i.e. router categories such as: full clone, restricted clone, port restricted clone, symmetric, etc). This complicates the NAT issue even further.

 

Firewalls:

Firewalls pose additional restrictions on VOIP and all other peer-to-peer network applications. The term firewall is often used generically. In short, a firewall is any software application/driver or hardware device that blocks incoming unsolicited traffic from the public network from entering intro a “protected” (private) network. Firewalls allow network traffic to flow out of the protected network and only allow traffic to come back in as the result of an internal request. This “one way” gating function of firewalls is so hostile to VOIP that it completely breaks the technology/protocol model associated with Voice over IP communications.

 

The successful deployment of a Voice over IP network relies on two distinct components: SIP session proxy support and RTP media proxy capability. With these two logical entities, you have the ability to deploy a Voice over IP infrastructure that will allow its users to overcome all issues associated with today’s hostile network environments. When you deploy the LanScape Centrex Proxy Server® and the LanScape VOIP Media Proxy®, you will be able to get your VOIP network up and running quickly and at a cost that pales in comparison to traditional leased line or legacy PBX environments.


Do I still need to deploy those expensive session border/boundary controllers?

Not anymore. By deploying LanScape Centrex Proxy Servers and LanScape VOIP Media Proxy servers, you no longer have to deploy session border controllers or session boundary controllers in your VOIP domain. Besides being very expensive network elements, they pale in comparison to a strictly software only solution. The LanScape Centrex Proxy Server® has integrated intelligence to reformulate SIP protocol packets and perform IP address and port fix-ups. This ensures that call sessions are always possible. The LanScape VOIP Media Proxy servers are then used to proxy media only when needed to make the exchanged of voice traffic a reality.


 

Additional Information you may find interesting:

Voice over IP is an exciting and new technology that is easy to apply and simple to use. However, let us assure you, the task of developing an implementation all of the underlying software technology in addition to creating robust telephony applications around these technologies is laden with idiosyncrasies and traps.

We here at LanScape have performed research and testing of many of the most current VOIP telephony technologies available. We have determined what has been successful and what has not. We have also performed studies that show what IP telephony functions and features are demanded the most and which features are very rarely used.

Like all new software technologies, the use and application of VOIP by end users and by the developers of product oriented companies can be a risky business. All of you reading this preface who are involved in the sales, marketing and development of software for your companies know how difficult “getting it right” is. Most often, developing a supporting technology needed by your end product or service ends up detracting you from the real task at hand. We have been there, we know.

In the ideal world, you would be able to design your product or service around off the shelf technologies in addition to your own internal software intellectual property. For most companies, the goal would be to minimize the time of the development and test cycles so as to deploy the end product/solution/service to the market as fast as possible. In most cases, this fast deployment allows quick feedback from the field relative to how well your team has met requirements. In this scenario, your company has the added advantage of realizing a revenue stream faster and minimizing risks associated with unfamiliar technologies. As time progresses over the life cycle of your product and/or service, your development team has the ability to “design out” any or all procured hardware and/or software technologies thus allowing you to achieve a pure, “wholly owned” product based completely on your hardware and software solutions.

That’s the ideal world. In reality, what most companies do is to identify technologies that work for them and their customers and stick with it. Typically, once a hardware or software solution is integrated into the final version of a product or service model, it often remains until the product/service has reached the end of its life cycle and is retired.

This is where LanScape’s VOIP technologies enters the picture. You have the immediate ability to plunge into the VOIP product sector with much reduced risk and diminished time requirements. You have the ability to enhance your products and end user experience using VOIP right now.  You can view the entire packetized voice telephony “function block” as a turnkey solution. If this is the first deployment of VOIP by your company, you will gain immediate positive results with a fraction of the effort. We cannot stress this enough. You will be able to remain true to your original task and remain focused on your end results.

Internet/packetized voice capability is a very interesting technology. VOIP can assist you in propelling your products into application spaces you might not have previously thought possible. As mentioned earlier, we here at LanScape have conducted studies over the past few years. To us it is clear and evident. Its not a question of “if” VOIP will be widely adopted, it is a matter of “when”. The “when” clause in most cases has already morphed into “now”.

For individuals new to voice over IP technology, the question most often asked is: “What minimum network infrastructure must I have to deploy VOIP?”. The answer is: “What you have right now”.

There are the VOIP “purists”, who claim you must have special quality of service monitoring and control in addition to a changeover of current equipment to support voice traffic. For most cases this is not true and is not a factor. Most residential and corporate networks are sitting there most of the time doing nothing. However, if you are in a network environment where you are already hitting the limit of your network resources, then yes, the network will have to be “built out” to support additional data carrying capacity.

Typical VOIP applications can be hosted on 10 or 100 Mbps Ethernet, 802.11 wireless LAN/access points, broadband, DSL, or other modest network connections having a minimum full duplex average throughput of 64kbps. If you have never experienced low latency VOIP telephony using 802.11 wireless Ethernet, then you are in for a pleasant surprise. The LanScape VOIP Media Engine™ was designed to directly address the needs of the above mentioned network infrastructures, especially the wireless network topologies.

The application of VOIP are indeed only limited to the extent of your imagination. If you are completely new to VOIP or telephony in general, sit back, read and absorb. Also, be prepared to receive the sense of accomplishment you will soon be experiencing as your new product or service allows your customers to do what they do best, communicate.

LanScape, Inc