Content Introduction ............................................................................................................................. 1 Voice over IP for Multi-Location Businesses ................................................................................ 1 Understanding Voice Networks ............................................................................................. 2 Public Switched Telephone Network ............................................................................
Voice over IP Primer Introduction Voice over the Internet Protocol (VOIP) is one of the hottest topics for multi-location businesses of any size because of its promise to transmit voice over data networks free of charge. Instead of paying the phone company to route long distance calls between offices, any IP data network can route the calls over a private intranet or the public Internet and save thousands of dollars annually. The ideal customer for this technology is a business with multiple locations.
In order to understand how voice communications would be treated in a data network, let’s first take a look at the typical topologies of voice and data networks running separately. Understanding Voice Networks Public Switched Telephone Network For the past 100 years, people have relied on the Public Switched Telephone Network (PSTN), otherwise known as POTs (Plain Old Telephone Service), for voice communication.
Another option is to provide the remote office with a key telephone system. A key system is a lower priced, reduced functionality version of the headquarters PBX. Because it is a scaled down system, it isn’t designed to be networked with other phone systems. Therefore, calling a remote office is like calling a separate company. Using our company example, the following diagram maps out their existing voice network.
Routers and IP Addresses A router is an advanced networking component that determines the route that IP packets of data will take. It has two separate, but related, jobs: • It ensures that information doesn’t go where it’s not needed. This is crucial for keeping large volumes of data from clogging the connection. • It makes sure that information does make it to the intended destination. In performing these two jobs, a router is extremely useful in dealing with two separate computer networks.
Using the Internet to Extend the Network Today, instead of simply dealing with local or regional concerns, many businesses now have to think about global markets and logistics. Many companies have facilities located across the country or even around the world. And, they all need a way to maintain fast, secure and reliable communications wherever their offices are. Before the Internet, this meant using leased lines to maintain a private Wide Area Network between the offices.
Understanding the Converged Network Voice over IP Voice over IP uses the data network packet-switching method to provide a more efficient way of sending voice communication. Packet-switching optimizes the use of network resources (bandwidth) because the channel is only occupied during the time the packet is being transmitted. Many users can share the same channel because individual packets can be sent and received in any order and the network can balance the load across various pieces of equipment.
The MultiVOIP Gateway The MultiVOIP family of Voice over IP gateways is available in analog and digital models ranging from one to 60 ports. MultiVOIP gateways connect directly to phones, fax machines, key systems, or a PBX and plug into the data network to provide real-time, toll-quality voice connections to any office on your VOIP network. With MultiVOIP, your customers will avoid the hassle and expense of replacing their existing routers, WAN connections or phone systems required by other VOIP solutions.
Voice over IP Frequently Asked Questions The following section covers some of the frequently asked questions a data communications manager or telecommunications manager may have as they begin to learn how a VOIP solution can solve their telephony challenges and save them money. Bandwidth Requirements “How can I be assured that my data “pipe” will not be flooded by voice traffic and negatively impact the timely delivery of data services?” One common misconception about VOIP is that it is a bandwidth hog.
Latency is defined as the average “travel” time it takes for a packet to pass through the network, from source to destination. The average time varies according to the amount of traffic being transmitted and the bandwidth available at that given moment. If the traffic is greater than the bandwidth available, packet delivery will be delayed. MultiVOIP deals with the latency issue in a private network as well as over the public Internet.
MultiVOIP also utilizes Bad Frame Interpolation to increase voice quality by making the voice transmission more robust in bursty error environments. It interpolates lost/corrupted packets by using the previously received voice frames. Interpolation of one or two voice packets will not cause a noticeable degradation in voice quality. Typically, Bad Frame Interpolation is invoked if Forward Error Correction cannot recover the lost/corrupted packets.
Ease of Use “Will my users require extensive training to use the MultiVOIP system?” No, placing calls with MultiVOIP is like using your existing phone system. It uses single-stage dialing by utilizing a Uniform Dialing Plan that is consistent with the E.164 (PSTN) standard numbering plan. This includes automatic appending and stripping of digits to dialed numbers to ensure that users will not require additional training to make VOIP calls.
Port Configuration “How do I determine the number of ports I need and which MultiVOIP to order?” You do not need a port for every telephone on the PBX system. You simply need to determine the calling ratio to determine how many ports you need at each location. The following guidelines can help you: 1) If you are replacing tie/trunk lines, for every line that you support you need one port on the MultiVOIP. Ex.
Voice over IP Applications MultiVOIP is ideal for multi-location businesses looking to reduce toll charges associated with intraoffice calling. It is designed to help a company maximize investments they’ve already made in their data network infrastructure and voice equipment. Using our company example, the following are some of the many applications for a VOIP network: Office-to-Office Communication A VOIP network can be as small as two offices or as large as hundreds of offices.
Wireless Connections To extend a customer’s PBX to a building across the street, utilize a wireless bridge to connect the two networks. Now, your customer has voice and data connectivity without laying cables or paying monthly charges for dedicated lines. Building off our example VOIP network, we have now added a wireless connection to the company’s warehouse. Wireless Building-to-Building 14 Copyright © 2003 Multi-Tech Systems, Inc. All rights reserved.
Configuring a MultiVOIP Network Now that you have a basic understanding of Voice over IP, the MultiVOIP gateway, and its applications, the next step is to learn how easy it is to configure the solution around existing telephone and data networks. Configuring the Telephony Interface Let’s first discuss how to configure the MultiVOIP gateway to the various telephony options. We will look at both the analog and digital MultiVOIP solution.
Key Telephone System and PBX Interface Options: 1. FXS interface - Use this interface when connecting the line side (CO port) of your key telephone system or PBX to the MultiVOIP gateway. The system will act similarly to connecting directly to a CO line. Here’s how it works: Outgoing calls: The caller needs to access the MultiVOIP gateway in order to receive a dial tone. An easy approach would be to associate a button on the phone system that will access the MultiVOIP gateway.
Building the VOIP Dialing Plan MultiVOIP provides single stage dialing by utilizing a Uniform Dialing Plan that is consistent with both the PBX and the E.164 (PSTN) standard numbering plan. This means placing calls is like using your existing phone system, no user training is needed. In order to accomplish this, MultiVOIP utilizes an Inbound and Outbound phonebook. In our company example, the system allows employees in any office to dial employees in any other office using only three digits.
When configuring the MultiVOIP gateway for the network, you must identify, within the software, its IP address, subnet mask, and gateway address. The IP address is your unique LAN IP address. The subnet mask is the number that identifies the sub network to which your MultiVOIP is connected. The gateway address is the IP address of the device connecting your MultiVOIP to the Internet/intranet.
Multi-Tech Pre-Sales and Post-Sales Support At Multi-Tech, we believe our resellers are truly an extension of our sales force. Therefore, we’ve put together a Voice over IP support program to provide you with both pre-sales and post-sales support. Optimum Reseller Program Our pre-sales support starts with our Optimum Reseller program. Once you sign on, you will receive a complete sales kit on Multi-Tech solutions. This kit includes contact information, product brochures, and other sales tools.
Warranty and Overnight Replacement Service The MultiVOIP product warranty is two years. In addition to our warranty, we offer an Overnight Replacement Service to eliminate concerns of downtime on the VOIP network*. The Overnight Replacement Service provides the following benefits: • Maximizes equipment reliability • Streamlines problem resolution • Includes all overnight shipping charges • One-time fee • 2-year coverage * For U.S. customers only. For more information, visit our web site at www.multitech.
VOIP Glossary of Terms Bad Frame Interpolation - Interpolates lost/corrupted packets by using the previously received voice frames. It increases voice quality by making the voice transmission more robust in bursty error environments. Bandwidth - The transmission capacity of a communications line. It is a factor in determining the amount of information and the speed at which a medium can transmit data or voice.
Internet Protocol (IP) - A protocol used to route data from its source to its destination in an Internet environment. It is a highly distributed protocol (each machine only worries about sending data to the next step in the route). IP address (or Internet Address) - A 32-bit address used by IP data networks to uniquely identify the location of a device on a network. Normally printed in dotted decimal format (e.g. 129.128.44.227).
Telnet - The TCP/IP standard network virtual terminal protocol that is used for remote terminal connection service and that also allows a user at one site to interact with systems at other sites as if that user terminal were directly connected to computers at those sites. T1 - A high-speed (1.544M bps) digital telephone line with the equivalent of 24 individual 64K bps channels time division multiplexed together.
Notes 24 Copyright © 2003 Multi-Tech Systems, Inc. All rights reserved.
MultiVOIP Voice Over IP Configuration Guide Headquarters Location: City: State/Prov.: Country: No. of remote locations 1. Configure Number of Ports Needed: MultiVOIP Model: A. Total monthly long distance bill: (Results from Line D = # of ports) B. % intra-office communication: E. Total monthly savings: (line A x line B) r r r r r 2. Bandwidth Needed: 3. Return on Investment: F. Voice Bandwidth: (line D x 14K) H. MultiVOIP cost: G. Total Bandwidth: (line F x 2) I. No.
Branch Office Location: City: State/Prov.: Country: 1. Configure Number of Ports Needed: MultiVOIP Model: A. Total monthly long distance bill: (Results from Line D = # of ports) B. % intra-office communication: E. Total monthly savings: (line A x line B) r r r r r 2. Bandwidth Needed: 3. Return on Investment: F. Voice Bandwidth: (line D x 14K) H. MultiVOIP cost: G. Total Bandwidth: (line F x 2) I. No. of months for payback (if unknown, the rule of thumb is 30%) C.
