dial-peer voice 44 pots service my_cool_script incoming called-number 40255511 port 1/1/0
CCVP GWGK Quick Reference Sheets
CCVP GWGK Quick Reference Sheets By Brion S. Washington ISBN: 1587053241 Publisher: Cisco Press
Prepared for Duc Le, Safari ID: [email protected] Licensed by Duc Le Print Publication Date: 2007/02/05 User number: 992496 Copyright 2007, Safari Books Online, LLC. This PDF is exclusively for your use in accordance with the Safari Terms of Service. No part of it may be reproduced or transmitted in any form by any means without the prior written permission for reprints and excerpts from the publisher. Redistribution or other use that violates the fair use priviledge under U.S. copyright laws (see 17 USC107) or that otherwise violates the Safari Terms of Service is strictly prohibited.
IP-TO-IP GATEWAY (IPIPGW )
IP-to-IP Gateway (IPIPGW)
The main points you need to understand about IPIPGWs are the serv- ices they provide for your network and the key reasons they are not considered normal voice GWs.
IPIPGWs offer services such as video support, interprotocol network- ing, address hiding, and better billing capabilities.
Billing can be simplified with the addition of IPIPGWs. Sometimes you need to bypass the PSTN and send VoIP between two VoIP networks. There are many names used to refer to this type of device: IP-to-IP gateway, border element, and session border controller. Wholesale VoIP resellers (WVR) or Internet telephony service providers (ITSP) use this method to connect to other VoIP resellers. One of the main reasons for implementing this kind of connection is for billing. When a WVR terminates calls between two other WVRs, the middleman misses out on billing opportunities because it does not control the terminating PSTN GW. The originating and terminating GWs see the call setup and release messages; the GWs in the middle do not. Both WVRs and ITSPs basically do the same thing, kind of like “tomayto or tomahto.” It’s all in how you perceive them.
IPIPGW can hide IP addresses of your service providers from customers, making your network look larger than it actually is. Address hiding can be a useful tool to expand your company’s size without actually buying more equipment. The reason I say this is your company can now offer more destinations to clients without the fear of clients acquiring the destinations from your service provider. This type of address hiding is widely used by wholesale VoIP companies.
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© 2007 Cisco Systems Inc. All rights reserved. This publication is protected by copyright. Please see page 63 for more details. CCVP GWGK Quick Reference Sheets by Brion S. Washington
IPIPGWs are used like other voice GWs in providing interprotocol networking. With interprotocol networking, you translate one type of VoIP protocol used by the calling party into a different protocol used by the called party. IPIPGWs work with H.323 or SIP and require special Cisco IOS (IPIPGW Image) software to perform these func- tions. Another functionality of these types of GWs is the capability to support video calls. Video codecs supported are Far-End Camera Control (FECC), H.261, H.263, and H.264.
The following figure shows an example and the likely steps used to provide IPIPGW in a real-world VoIP network.
V Company Z Company A Company D Chicago IPIPGW V V FIGURE 1.13 WVR Example
1.Company A is a small company of five employees. They would like to enter the wholesale VoIP / ITSP market. Company A buys a Cisco MultiService Gateway.
2.Company A buys a route from Company D to Chicago. 3.Company A is assigned a tech prefix of 333313# by Company D.
CCVP GWGK Quick Reference Sheets
CCVP GWGK Quick Reference Sheets By Brion S. Washington ISBN: 1587053241 Publisher: Cisco Press
Prepared for Duc Le, Safari ID: [email protected] Licensed by Duc Le Print Publication Date: 2007/02/05 User number: 992496 Copyright 2007, Safari Books Online, LLC. This PDF is exclusively for your use in accordance with the Safari Terms of Service. No part of it may be reproduced or transmitted in any form by any means without the prior written permission for reprints and excerpts from the publisher. Redistribution or other use that violates the fair use priviledge under U.S. copyright laws (see 17 USC107) or that otherwise violates the Safari Terms of Service is strictly prohibited.
IP-TO-IP GATEWAY (IPIPGW )
4. Company A sells VoIP minutes to Company Z for calls to Chicago. 5. Company Z is assigned a tech prefix of 55# by Company A. 6. Company Z has end users (callers) with family calling the Windy
City. Calls are sent to Company A’s IPIPGW IP address with a tech prefix of 55#.
7. Company A’s IPIPGW strips off 55# and forwards digits with 333313# appended to Company D’s IPIPGW.
8. Call detail records (CDR) are checked on all minutes from Company A’s IPIPGW for billing.
You can repeat Steps 2 through 8 as many times as necessary for each new route or company you add. The only thing that will stay constant is the tech prefixes assigned. The tech prefixes are assigned only once, when the first route is added, and remain the same throughout the busi- ness relationship.
So, Company A now looks like a big WVR or ITSP, without the need to have equipment located in every destination they want to offer. There are advantages and disadvantages to this style of business.
Advantages Disadvantages
Centralized billing No control of remote networks Centralized security Limited quality of service support Low investment to start up Test every new route
Unlimited growth potential Constantly changing providers
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© 2007 Cisco Systems Inc. All rights reserved. This publication is protected by copyright. Please see page 63 for more details. CCVP GWGK Quick Reference Sheets by Brion S. Washington