Alright in this video we're going to talk a little bit about Frame Relay. I know you might be thinking, well I'm taking a routing course, why am I learning about Frame Relay? I just want to jump in and mess with all the routing protocols, I want to learn EIGRP and BGP and all these nice other protocols. Well the reason you have to learn Frame Relay is it's a foundation technology. Even if you move on to ATM or MPLS networks a lot of the terminology and a lot of the concepts come from the Frame Relay world. And if you know Frame Relay and you're familiar with it's concepts then you can easily move onto ATM or MPLS which is the, the latest and greatest technology in wide area networking. And truth be told, even though a lot of providers will sell you an MPLS connection, on the physical layer it's actually provisioned as a Frame Relay connection. I know of at least two networks, two wide area networks that are provisioned this way. Now Frame Relay for those that are unfamiliar with it, uses the concept of Virtual Circuits. Instead of having a physical Point-to-Point Circuit between every location on your network, you have everything brought in over a Virtual Circuit. Since it is a Virtual Circuit coming in over a single physical connection, you're going to have a lot cheaper infrastructure than if you had to have 200 T1's coming into a centralized location. If you do that, you have to have four or five routers each with 20 or 30 interfaces or you're going to have to slice up a DS3 or a higher speed network connection into multiple T1's or T1 bundles. If you have a Virtual Circuit, you just connect to the Frame Relay providers Cloud and you just send all of your traffic over a gigabyte connection for example. It allows you to be more flexible in your configuration also. If you have a Virtual Circuit coming into your location and you need to spin up another location real quick, well you just have to worry about getting a local T1 at that local end to connect to the Frame Relay point of presence in that remote location and they just dump the traffic into your Frame Relay network and it comes back into your hub center and away you go. Now not only does it allow you as the customer to have a cheaper connection and more flexible, it's also better for the provider as well. The provider can more efficiently utilize the available bandwidth inside their network and basically it all just boils down to, no one uses 100 percent of their bandwidth 100 percent of the time. For example, if you have two sites and you have a T1 between those two sites, the phone company or the Tell co has dedicated 1.544 megabyte of their network between your two locations. You may only use 768k or one megabyte on any given day but they have that bandwidth dedicated to you. If you're using a Frame Relay network and you're dumping all of your data into their Frame Relay network, then they can combine your data with everybody else's data and make more efficient use of their backbone resources. Of course, the dirty little secret is, is this means providers can over sell their bandwidth. Let's say they have a one gigabyte fiber ring inside a city and they're wanting to sell time on that fiber ring, well they could sell four or five gigabyte worth of Frame Relay Connectivity on that fiber ring and since no one uses 100 percent of their bandwidth all the time, the chances that your data would be delayed are, are pretty slim. So I've mentioned the term Virtual Circuit and Virtual Circuits are basically just logical paths between routers. There are two types of Virtual Circuits. You have a PVC or a Permanent Virtual Circuit, that's a Circuit that's nailed up and available for your network use all the time. You also have a SVC or a Switched Virtual Circuit which may or may not be available to you until it's actually needed. And now comes the part of the slide show presentation where I'm just dumping terms at you. These are some of the Frame Relay terms that you'll need to know to better understand the next few slides where we talk about network overviews and network connectivity. The first is the Access Rate and the Access Rate is the speed of the local link between your router, you being the customer and the Frame Relay Switch that the provider has set up for you. That could be a T1, it could be a fractional DS3, it could be a 256k connection. That is the speed that you'll configure your local physical interface for. You also have the Committed Information Rate and that's the rate that the Frame Relay provider will guarantee for delivery across their Frame Relay network. Now the CIR is generally less than the Access Rate. For example, if you have a full T1 as your access rate, 1.5 megabyte, the provider may say, well we'll only guarantee that 768k will go across our network reliably. Now can you use the full T1, absolutely, but if there's contention on the network, they're only guaranteeing that 768k of your traffic will get through in a timely manner. Now what traffic you put into this CIR bucket if you will, is really up to you. You can tag certain traffic to say, I always want this traffic to be delivered, say it's your VOIP or your mission critical applications for your business, so you can mark those packets and you can tell the Frame Relay provider, I always want those packets to be delivered and the rest of the stuff, the web browsing and the email, not so much. The next term we'll look at is the Data Link Connection Identifier or the DLCI. That is a logical Frame Relay address and we'll go over that on the next slide when we talk about network topologies and finally we have the LMI or the Local Management Interface and that is the communications protocol that is used between the customer equipment, your equipment and the providers Frame Relay Switch. Really the only important thing you have to know about LMI is that it has to match on both ends. It's either Cisco or ANCI and so long as it matches on both sides, that's really all you have to worry about. We'll continue with our discussion of Frame Relay Basics in the next video.
|Course:||Implementing Cisco IP Routing (Exam 642-902 ROUTE)|
|Duration:||10 hrs / 105 lessons|
|Captions:||Available on CD and Online University|
WIN XP SP3, OS X 6+, Android 4, iOS 4, Linux
TERMS & CONDITIONS OF USE
BY SUBSCRIBING TO THIS SERVICE, YOU ARE CONSENTING TO BE BOUND BY AND ARE BECOMING A PARTY TO THIS AGREEMENT, THE TERMS AND CONDITIONS OF WHICH SHALL PREVAIL IN GOVERNING YOUR RIGHTS OF USE. BY CLICKING THE "BECOME A MEMBER" BUTTON, THE INDIVIDUAL OR ENTITY LICENSING THE PRODUCT ("YOU") IS CONSENTING TO BE BOUND BY AND IS BECOMING A PARTY TO THIS AGREEMENT. IF LICENSEE DOES NOT AGREE TO ALL OF THE TERMS OF THIS AGREEMENT, THE BUTTON INDICATING "BECOME A MEMBER" MUST NOT BE SELECTED, AND LICENSEE MUST NOT INSTALL OR USE THE SOFTWARE.
"VTC" refers to Virtual Training Company,
"You" refers to the user or subscriber.
"Software" refers to the VTC training content and software.
2. LICENSE: VTC hereby grants to You a worldwide, non-royalty bearing, non-exclusive license to use the Software according to the provisions contained herein and subject to payment of the applicable subscription fees.
3. RESTRICTIONS: You may not do any of the following:
Save the Software to Your hard disk or other storage
medium; permit others to use the Software except as specified by addendum;
modify, reverse engineer, decompile, or disassemble the Software; make
derivative works based on the Software; publish or otherwise disseminate
the Software. VTC, Inc., VTC Online University, and the Virtual Training
Company site is owned and operated by VTC, Inc. as a corporation of
All materials on this site are the property of VTC unless otherwise specified. No material from these pages may be copied, reproduced, republished, downloaded, uploaded, posted, transmitted, or distributed in any way. Modification of the materials or use of the materials for any other purpose is a violation of U.S. copyright law and other proprietary rights. For purposes of this Agreement, the use of any such material on any other web site or networked computer environment is prohibited.
4. FEES: The rights granted under this Agreement
are effective only upon payment of the subscription fees, which are
strictly non-refundable other than as expressly provided herein. The
term "monthly subscription" is defined as any 30 day period.
The term "yearly subscription" is defined as one 365 day
period. A yearly subscription ends on the same numerical date as it
began (example July 28, 2004 to July 28, 2005).
The VTC Online University is access to every VTC training tutorial in our library. You pay a flat fee for access to these titles. You are billed according to your renewal selection below, and can renew monthly, yearly, or in any other increment offered. If you choose to be billed monthly, you will be billed every 30 days for the subscription until you request the subscription be cancelled. Our terms of service state that you must cancel a monthly subscription at least two business days before your renewal date. These two days give us enough time to ensure that you will not be charged again.
5. LIMITED WARRANTY: VTC warrants that the Software, if operated as directed, will substantially achieve the functionality described. VTC does not warrant, however, that Your use of the Software will be uninterrupted or that the operation of the Software will be error-free or secure. In addition, the security mechanisms implemented by the Software have inherent limitations, and You must determine that the Software sufficiently meets Your requirements. VTC also warrants that the media containing the Software, if provided by VTC, is free from defects in material from the date You acquired the Software. VTC's sole liability for any breach of this warranty shall be, in VTC's sole discretion: (i) to replace Your defective media or Software; or (ii) to advise You how to achieve substantially the same functionality with the Software as described; or (iii) if the above remedies are impracticable, to refund the subscription fee You paid for the Software. Only if You inform VTC of Your problem with the Software during the applicable subscription period will VTC be obligated to honor this warranty. VTC will use reasonable commercial efforts to repair, replace, advise, or refund pursuant to the foregoing warranty within thirty (30) days of being so notified. If any modifications are made to the Software by You during the warranty period; if the medium is subjected to accident, abuse, or improper use; or if You violate the terms of this Agreement, then this warranty shall immediately terminate. This warranty shall not apply if the Software is used on or in conjunction with hardware or software other than the unmodified version of hardware and software with which the Software was designed to be used as described.
THIS IS A LIMITED WARRANTY, AND IT IS THE ONLY WARRANTY MADE BY VTC OR ITS SUPPLIERS. VTC MAKES NO OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NONINFRINGEMENT OF THIRD PARTIES' RIGHTS. YOU MAY HAVE OTHER STATUTORY RIGHTS. HOWEVER, TO THE FULL EXTENT PERMITTED BY LAW, THE DURATION OF STATUTORILY REQUIRED WARRANTIES, IF ANY, SHALL BE LIMITED TO THE ABOVE LIMITED WARRANTY PERIOD. MOREOVER, IN NO EVENT WILL WARRANTIES PROVIDED BY LAW, IF ANY, APPLY UNLESS THEY ARE REQUIRED TO APPLY BY STATUTE NOTWITHSTANDING THEIR EXCLUSION BY CONTRACT. NO DEALER, AGENT, OR EMPLOYEE OF VTC IS AUTHORIZED TO MAKE ANY MODIFICATIONS, EXTENSIONS, OR ADDITIONS TO THIS LIMITED WARRANTY.
6. PROPRIETARY RIGHTS: VTC reserves all proprietary rights in and to the Software, is protected by copyright and other intellectual property laws and by international treaties. VTC, Inc.
Trademark Notice: VTC, Virtual Training Company,
Inc., The VTC Logo, and VTC Online University, are trademarks of VTC,
Inc. All other company and product names may be trademarks of their
The information contained herein is subject to change without notice. Copyright © 1995 - 2005 VTC, Inc. All rights reserved.
7. TERMINATION: This Agreement shall automatically terminate if You fail to comply with the restrictions described herein. Your obligations to pay outstanding subscription fees shall survive any termination of this Agreement.
8. LIMITATION OF LIABILITY: UNDER NO CIRCUMSTANCES
AND UNDER NO LEGAL THEORY, TORT, CONTRACT, OR OTHERWISE, SHALL VTC
OR ITS SUPPLIERS OR RESELLERS BE LIABLE TO YOU OR ANY OTHER PERSON
FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OF
ANY CHARACTER, INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF GOODWILL,
WORK STOPPAGE, COMPUTER FAILURE OR MALFUNCTION, OR ANY AND ALL OTHER
COMMERCIAL DAMAGES OR LOSSES. IN NO EVENT WILL VTC BE LIABLE FOR ANY
DAMAGES IN EXCESS OF THE AMOUNT VTC RECEIVED FROM YOU FOR A LICENSE
TO THE SOFTWARE, EVEN IF VTC SHALL HAVE BEEN INFORMED OF THE POSSIBILITY
DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY. THIS LIMITATION OF LIABILITY SHALL NOT APPLY TO LIABILITY FOR DEATH OR PERSONAL INJURY RESULTING FROM VTC'S NEGLIGENCE TO THE EXTENT APPLICABLE LAW PROHIBITS SUCH LIMITATION. SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THIS EXCLUSION AND LIMITATION MAY NOT APPLY TO YOU.
9. Links To Other Materials: Linked sites found at the VTC site are not under the control of VTC, and we are not responsible for the content of any linked site or any link contained in a linked site. VTC may change links based solely on our discretion, and we reserve the right to terminate any link or linking program at any time. VTC does not, by linking to sites, endorse companies or products to which it links and reserves the right to note as such on its web pages. If you decide to access any of the third party sites linked to this site, you do this entirely at your own risk.
Forums, and Chat are not always screened by VTC, and we are not responsible for the content of any public or open forum content at the site. VTC may change these public forums based solely on our discretion, and we reserve the right to terminate any forum at any time. VTC does not, by allowing these forums, endorse companies or products which may be mentioned in these forums, and reserves the right to note as such on its web pages. If you decide to access any of the public forums in this site, or linked to this site, you do this entirely at your own risk.
9. GOVERNING LAW & DISPUTE RESOLUTION: This Agreement is governed by Virginia law. All disputes between You and VTC shall be finally resolved through arbitration in Winchester, Virginia. This site is controlled by VTC from its offices within the United States of America. VTC makes no representation that materials in the site are appropriate or available for use in other locations, and access to them from territories where their content is illegal is prohibited. Those who choose to access this site from other locations do so on their own initiative and are responsible for compliance with applicable local laws. You may not use or export the Materials in violation of U.S. export laws and regulations. Any claim relating to the Materials shall be governed by the internal substantive laws of the Commonwealth of Virginia, USA.
VTC may revise these Terms at any time by updating this posting. You should visit this page from time to time to review the then-current Terms because they are binding on you. Certain provisions of these Terms may be superseded by expressly designated legal notices or terms located on particular pages at this Site.
If you have any questions regarding this policy,
or your information specifically,
you may email us at:firstname.lastname@example.org.