SIP Versus ISDN
What is SIP Trunking? In simple terms a SIP Trunk is a VoIP service that connects your PBX to the PSTN using the internet. IP PBX DS L, Di rect Internet or Ethernet Foehn s SIP Trunking Service Public phone network Your P remises Your Equipment Access Se rvice/network Why SIP over ISDN? For any small to medium sized business looking to move premises, upgrade or replace their telephone system, the level of choice can be bewildering. But for businesses, driven by cost reduction, customer service and remote working, the advancements in technology and the internet have undoubtedly expanded and the improved the choices open to them. One of the choices to consider is the right access network. Once companies would have queued to buy expensive Automatic Call Distributors (ACDs) and ISDN lines, nowadays they re looking for simpler and more cost -e ective solutions. While ISDN digital transmission over copper lines was t for purpose then, it now looks increasingly restrictive and expensive for those call centres yet to deploy alternatives especially with more economic alternatives such as SIP in their sights. Companies often fail to cancel ISDN channels when they are no longer required, resulting in signi cant line rental charges. ISDN is now facing tough competition from easy -to-use and scal able IP services such as SIP. For a call centre manager or customer service director, exibility is key. They need to be able to scale numerous channels up and down to account for seasonal ctuations and peak demand such as during Christmas. With ISDN, exibility wasn t easy, you d have to pay extra for increased lines during peak periods but these would be unused during low season. Businesses need to ask themselves who is it that has the motivation to reduce the cost of ISDN? The reseller? The network provider? The call centre operator needs to take responsibility for squeezing cost out of the business in such economically challenging times. Unlike ISDN, the bene ts of SIP Trunking are easy to grasp and visible for all to see. ISDN is a legacy technology and businesses that fail to replace it will become increasingly disadvantaged in terms of service quality, business agility and pro tability. 2
SIP versus ISDN WHY SIP OVER ISDN? ISDN SIP Leads times 6 weeks 48 hours Granularity of scale Less flexibility as demand Line by line as you need. needs to be estimated and Can be scaled up or down lines ordered weeks in on demand quickly advance Networks Disaster recovery plan Separate networks for Single converged voice and data network Need for redundant Disaster recovery, call circuits re-routing easy to implement Numbering Cost Geographically defined, Geographically unless additional NGNs independent- you choose purchased your preferred STD code 2496 511 Calls charged between Intra-site calls free sites unless a VPN built in using SIP (10 channels, 20 DDIs, 12 month contract) Call charges 3
SIP vs ISDN INSTALLATION TIMES SIP ISDN30 DAYS Advantages of SIP Trunks Converged voice and data network The transportation of voice uses IP (the communication protocol data networks run on) therefore the management and control of a single network reduces complexity and overhead. Easy and e ective disaster recovery planning SIP trunks provide far higher redundancy. In the event of a failure at the customer site or the provider the traffic can be instantly routed to a different location. This can be useful for disaster recovery plans. Load balancing and multiple outbound routes If you have a high volume of traffic load balancing and multiple outbound routes can be provided to ensure the traffic volume can be met. (In a legacy world this would mean multiple point to point lines with separate backup circuits- a cabling nightmare!) Consolidation and Flexibility SIP isn t geographically dependent so you can bring London numbers to Glasgow and Blackpool numbers to Bournemouth, thereby greatly reducing the requirements at each site. Quicker to deploy and scalable SIP gets installed quicker (Typically within 48 hours vs. six weeks for an ISDN line). SIP can scale up and down on demand something that just isn t possible with ISDN. Barriers to using SIP Our PBX doesn t support SIP It s often said but this is easy to resolve with a low cost IP gateway platform. Perhaps you re in a contract already Depending on the length of this commitment this needn t deter you. Call charges from SIP Trunk providers are often significantly lower than those charged by incumbent legacy service providers. This advantage may outweigh any early termination fees. We don t have the data line to support SIP If you have an existing connection to the internet; there are the capabilities to get you up and running quickly with technology to provide guaranteed quality of service. 4
Foehn s solution was not only the most competitively priced, but it also promised a centralised management system guaranteeing cost savings in the long term. Jonathan Bastin - Head of IT at Low Cost Travel Group A customer service centre of popular online ticketing company needs a communications system that grows as quickly as we do. Foehn s solution does that. Russell Morris - Head of IT at See Tickets Foehn provided us with a strategic platform for growth and a modern communications system for to-day-which they continue to manage for us Keith Fernett Director at Anchor House 5