FAQ 1How are savings made in PVDTN?The voice to non-voice (fax and data)communications cost ratio varies as underbased on statistics collected for various MLOs(multi-locational organisations across theworld. 80:20 for the most developed countries 95:5 for developing countries 97:3 for less developed countriesSince for the same unit of time 60 times moreinformation can be transported as data theVolume ratio would look like 80:1200 for the most developed countries 95:300 for developing countries 97:180 for less developed countriesThere is one other ratio the inter-locational (orintra-company) communications costs to totalcommunication costs. This could vary fromabout 40% for small and less inter-activeMLOs (multi-locational organisations) to 80 to 90% for large and highly inter-active MLOs.
FAQ1(Contd.)Thus if the total communication (voice and data)costs of a company like yours is X the cost ofvoice communications will be around 95% andthat of data around 5%. The integrated voice-data intra-net will carry only the inter-locationalvoice traffic and the total data traffic which ismostly internal. Even external email will bepassed through this network to be conveyed tothe internet gateway through the STS system.The total cost of inter-locational communicationof a company is = T + D, where T is the inter-locational telephony and fax cost and D is thedata communications cost. In this case T will besay 0.8 x 0.95 X = 0.76 X ; and data com costwill be 0.05 X.What PVDTN does is that it eliminates T, byadding a percentage of D to D. Thus in placeof T+D as you have now, for inter-locationalcommunications costs, you will have D + d ( apercentage of D) for total inter-locationalcommunications costs with PVDTN. Furtherpresently T varies with increased usage andconsequently (T + D) increases year by yearwith increased usage. (D + d) on the otherhand will be a fixed per annum cost forunlimited usage. There are no usage charges.
FAQ 2 In our company the voice and fax services are looked after by one group, and the data services are looked after by another group. Since PVDTN is an integrated voice / fax / data network what will happen to this arrangement?In PVDTN over the same point-to-point leasedline backbone we have two separate anddistinct networks running. A circuit switched network for voice and fax communications through the VDPS (EPAX with E&M trunk cards). A packet switched IP network through the data routers sitting on the computer LAN at each location.The bandwidths for each network are providedby the channels splitter at each location.The above are clearly explained in Slide 2, ofPVDTN Presentation.Thus your present voice communication teamwill look after the circuit switched voice and faxnetwork for inter-locational communications andthe PSTN infrastructure already in place.The IT / data communications team willadminister the packet switched IP data networkthrough the data routers and the PVDTN WAN,and also the Internet connectivityThus there is no conflict of roles or interest ofeither group of people.
FAQ 3 We have already implemented voice integration over our existing data network using VOIP (voice over IP). How can PVDTN improve on this?In VOIP (voice over IP) the actual bandwidthrequired per each call through the WAN is 90 to100 kbps. In the circuit switched network thebandwidth required for each call through the circuitswitched WAN is either 12.8 kbps or 24 kbpsdepending on the multiplexers (channel splitter)being used.Thus considerably larger link bandwidth is requiredfor VOIP leading to higher operating costs. Use ofPVDTN integration will reduce the linkbandwidth and hence the operating cost.Irrespective of VOIP or PVDTN integration thenumber of simultaneous calls to be provided in anyWAN link is determined by Erlang loading, which isthe number of extensions to be served by eachtrunk (WAN call). This could vary from 1:6 (for verybusy locations), to 1:10 (for normal locations as in astandard PSTN network). For most multi-locationalorganisations (MLOs) 1:8 is a good Erlang loadingratio.Thus if there are 96 users of NET telephones in alocation based on Erlang loading of 1:8, thereshould be 12 simultaneous WAN calls or trunksprovided for. These may be distributed over all thelines terminating at the location.
FAQ 3 (Contd.)The total bandwidth required for evacuatingthese simultaneous WAN calls will be 1200kbps for VOIP and 154 or 288 kbps for PVDTN.If the appropriate bandwidths are not providedin VOIP it will amount to bandwidth jammingand resulting unsatisfactory speech quality.And in PVDTN it could cause blocking ofcommunications.Provision of the appropriate bandwidth ensuresunblocked communications in PVDTN andsatisfactory speech quality in VOIP.In most VOIP implementations this aspect isoverlooked resulting in bandwidth jamming andunsatisfactory speech quality.This is what prompts the NET phone users tofall back on their PSTN phones to speak totheir colleagues in other organisation locations,increasing telephony costs.In PVDTN bandwidth provision is alwaysoptimum resulting in unblocked toll quality(normal telephone like) speech. Thus PSTNcalls to other company locations are totallyeliminated.
FAQ 4 How do we run our Web based collaboration tools on PVDTN?♦ PVDTN is a combination of two parallel networks. ♦ A circuit switched network for normal telephony and fax communications (synchronous communications) ♦ An IP packet switching network for data and and other IP communications (asynchronous communications).♦ All collaboration tools and software will run on the IP network for collaboration within the organisation, with the software residing in a server housed within the Intranet. This may be done using Novell Teaming and Conferencing , Microsoft Share Point, etc.♦ For collaborative work with the outside world – clients, vendors, consultants, the Internet would be used through the IBN (Internet Browsing Nodes). For this there are two options. ♦ Use Web based meeting portals like Mediatone Networks Webex (there are several other similar shared collaboration solutions portals). ♦ Set up your own Web based collaboration server in the Company’s Web based Public server and carry out collaborative activity with the Company’s clients ,vendors, consultants, business partners. This may be done using Novell Teaming and Conferencing, Microsoft Share Point, etc.