CRM, BPO & Teleservices

The IP Switch

By Brendan B. Read, Senior Contributing Editor  |  June 01, 2011

In buying voice services contact centers are gradually switching from PSTN/TDM to Internet Protocol (IP), most commonly using session initiation protocol (SIP) or SIP trunking. The day that PSTN’s copper-intensive hardware will join cordboards and electro-mechanical switches as museum pieces is not too distant.

The key reasons for the IP switch are cost savings and increased flexibility such as ease of on-the-fly routing and supporting home agents. IP quality and reliability has been improving – though still not yet at the same “five nines” level as PSTN – as technologies develop.

Many contact centers use QoS (quality of service) voice traffic prioritization on MPLS (multiprotocol level switching) networks. Yet others are comfortable with using lower-priced if lesser quality open Internet for IP; the argument has been made that growing cellphone use has created a degree of tolerance for unclear calls, at least until HD Voice becomes widespread.

The carrier marketplace is responding. There are SIP trunking providers and traditional local and long distance firms that are competing intensively for this business with a widening array of competitively-priced services.

Jim Koniecki, technical consultant of unified communications and collaboration for Dimension Data, predicts that by 2015, 60 to 70 percent of contact centers will use SIP trunking versus traditional TDM circuits. 

“There will be pressure by the carriers even the incumbents to move customers like contact centers from TDM to SIP,” says Koniecki. “This is due to the higher costs of carrier and customer maintenance for these legacy TDM systems, for which less equipment is being developed, manufactured and supported.”

Andy Bird, inContact senior solutions manager, reports that his firm is seeing additional requests for VoIP/SIP. The smaller contact centers were the early adopters, he points out, but now there are some of the largest companies that are considering employing these solutions. 

“The market is clearly demanding more SIP and VoIP connectivity due to the need for reducing costs and increasing functionality,” says Bird. “Although QoS is still a dominant requirement, we are seeing that the market also wants a non-QoS open Internet VoIP option. This has been increasing over the last few years. Customers are willing to give up quality for an Internet-based solution.”

The IP/SIP Drivers

The big move to IP/SIP is its appeal of cost savings, flexibility and its openness. While PSTN rates have plummeted principally from IP/SIP competition there are still expense reductions to be had. SIP-based VoIP is considered a data service, reports Dimension Data, and is not subject to the same tariffs, fees and taxes as traditional PSTN and is largely unregulated at this time.

Lawrence Imeish, principal consultant at Dimension Data says with SIP – and unlike with PSTN – one can pool inbound and outbound in minutes, regardless of geography or even country one expects to buy, especially if the traffic is being handled by one national SIP carrier. This method drives down per-minute costs substantially.

Another savings source is DID (direct inward dial) line management self-service that is practical only with IP/SIP. Contact centers can port or migrate DID lines between different carriers or move between offices, between agents and sometimes back and forth between SIP and PSTN links – when supported by the carriers – instantly. In contrast, during the PSTN-only days, contact centers had to have the carriers provision them to readily interface with the CO switches which would take up to 30 days.

IP/SIP also offers improved and more cost effective routing between multiple contact centers by enabling managers to quickly and easily pre-route incoming calls. With PSTN firms have (or had) to buy separate circuits from the individual incumbent local exchange carriers in the areas where their contact centers are located. That meant getting them to talk to each other to balance the loads. Pre-routing PSTN calls is usually done by carriers, although at considerable expense. 

The savings from these moves can be significant. One of Dimension Data’s clients, a large southern U.S.-based bank, had several different local and long distance carriers. They then consolidated to a single SIP/IP carrier, resulting in a nearly $1 million per year savings, along with a 25 percent drop in voice costs over what they had been paying in PSTN circuits. 

“You can still do this PSTN but you’re paying your carriers a fair amount of money to bring this traffic across whereas now one SIP provider can do this all seamlessly,” says Imeish. 

IP/SIP also permits more cost effective home agent support than PSTN; with it, long distance charges are minimal and there is no need for costly added pipes. For example, this flexibility allows cost-effective deployment of seasonally-needed home agents.

8x8, in partnership with Contactual, enables its clients to turn on services for specific periods of time. 8x8 provides the entire service, including call routing and access to the contact center platform. Contact centers pay a significantly reduced fee when the service is not being used while still maintaining its tenant specific configuration and phone numbers so that it can be reinitiated at a moment's notice with no startup costs.

Another driver to IP/SIP is that it enables contact centers to provide increased integrated and seamless multichannel chat, e-mail, IM, SMS/text and video as well as voice collaboration with customers and colleagues. Unified communications (UC) that relies on IP permits agents to bring on board subject matter experts – who can be located anywhere – into customer interactions.

 “PSTN is a static service,” says Jeff Betteker, COO of One Source Networks. “It doesn’t offer companies the flexibility and cost-savings let alone feature-rich services that a SIP platform enables.”

IP Quality and Redundancy

Most contact centers are still on PSTN as they are concerned about IP voice quality, an issue inContact’s Bird says is compounded when calls go overseas. Longer calls, because agents and callers not understanding each other, and dropped calls cost centers money both directly through added interaction lengths and indirectly via annoyed customers and potential missed sales. 

“Open internet VoIP is still an issue,” says Bird. “The best practices still require a router at the customer's site for best effort routing.”

Many contact centers are instead provisioning dedicated voice MPLS circuits to transport SIP calls, report Imeish and Koniecki. These circuits connect them to their SIP providers directly for the highest possible quality and lowest latency.  

SIP over the public Internet is possible is but more bandwidth is recommended since QoS mechanisms is best effort; VPNs or session border controllers (SBCs) should be used to encrypt the traffic. While using a dedicated MPLS network provides the same quality and resiliency of traditional of PSTN networks it also increases costs. To offset, larger contact centers can have the cost of their voice MPLS connectivity bundled into their SIP providers’ monthly bills, says Koniecki.

To enable QoS 8x8 employs a variety of methods. These range from simple mechanisms such as Class of Service (CoS) tagging on the LAN – which it says solves most issues for smaller contact centers – to provisioning private or MPLS broadband connections to guarantee end-to-end QoS. Availability – which is related to quality – is also guaranteed by 8x8; the use of redundant data centers provides even small contact centers with a highly reliable service at minimal cost without the need for IT support from the contact center customer.

M5 only provisions its primary customer locations using private line "on net" connectivity. There is no public Internet VoIP, with no opportunity for jitter, packet loss and diminished QoS.

“Contact centers depend upon phone service, so voice quality and reliability are essential,” says Jeff Valentine, M5 senior vice president of product marketing.

Yet in totality quality is fading as an issue. Networking hardware, DSPs and codecs have matured and become more reliable. To be sure Koniecki recommends that contact centers evaluate carriers instituting QoS and employing network monitoring and testing software.

Moreover, IP/SIP it can be argued offers greater reliability than PSTN because it offers many more routes available in a network. With IP/SIP if one signaling server, say on the East Coast goes down, such as from a fiber being cut there is probably 15 or 20 other signaling servers on a carrier’s SIP network, explains Koniecki. With PSTN this degree of redundancy, which relies on copper wires and maintaining continuous circuits is not practical. SIP voice traffic reaps the benefits of IP’s existing ubiquity and redundancy.

“With the right combination of planning, ISPs, SIP providers, hardware and monitoring, contact centers can confidently use SIP trunking with VPNs to deliver voice over the public Internet,” says Koniecki.

Ben Navon, president and CEO of Optimized Business points out that as long as the bandwidth is in place, VoIP is extremely reliable and provides the technology for fallback routes. He is seeing contact centers switch over to VoIP once they have tested it; they recognize the major improvement in the call quality versus other lines. And he adds there are universal benefits to using VoIP, such as reporting, tools, conversion and product simplicity as well dramatic cost savings.

“The only concern that contact centers may have is the reliability of VoIP,” says Navon. “Everyone that starts using VoIP at any given point in the past, very quickly forgets about these concerns.”

The Carrier Market

Carrier services, driven by IP firms are becoming competitive and versatile. TNCI offers the TNCInet Private IP Network Solutions (News - Alert) which includes dedicated long distance, integrated voice and direct Internet access. Contact centers can converge all of their voice, data and Internet applications onto a single private IP network. TNCI (News - Alert) uses MPLS VPN for dedicated Internet access with integrated voice services including analog, PRI/CAS as well as SIP trunking. The TNCInet Dedicated LD Solution for Call Centers features a 15 second average length of call requirement and extremely aggressive rates as low as $.0099.

Carriers – and contact center services – have been expanding outside of the U.S. InContact has expanded to Europe and has implemented patent-pending voice gateway technology to help improve call quality. This will eliminate static and voice delay problems frequently experienced by other providers who do not have infrastructure in the region, improve service to existing customers, and offer a competitive advantage for prospective new multinational accounts.

Carriers continue to make improvements to their IP/SIP networks. One Source Networks has deployed the Sonus GSX9000 high-density media gateway with NBS SBC functionality and the Sonus PSX Centralized Routing and Policy Server. These tools permit the firm to manage and scale their network more easily and efficiently through enabling centralized routing. This method provides consistent service globally and disaster reliability through fully redundant architectures via separate policy servers.

The Sonus solutions also support transitioning contact centers from TDM to IP. They allow them to implement network architectures that support routing and signal interworking between any IP-PBX (News - Alert) or ACD.

Others are enabling call-quality-conscious contact center customers to bypass the public Internet. Broadvox uses Covad's IP Backhaul Aggregation Service and Ethernet access services to deliver, prioritize and segment voice traffic. The service provides a high-speed connection to Covad’s nationwide private IP network.

8x8 has introduced new bundled affordable carrier offerings that make it easy for contact centers to get started with basic voice functionality. They can then upgrade to more advanced functionality (i.e. chat, e-mail and fax queueing) as their needs mature or their business changes.

IP carriers are now offering sophisticated hosted contact center solutions. One of the most recent of these is M5’s purchase of Callfinity. New features include prioritized skill routing, an online evaluation forms designer for quality management, extensive IVR capabilities, CRM integration support, and both real-time and on-demand contact center reporting and analytics. Callfinity products are deeply integrated within M5's core hosted and managed VoIP offering for seamless service.

The incumbent local and long distance carriers are getting into the game as SIP trunking carriers and for good reason. Not only are the SIP trunking firms taking additional profits from them – while generating revenue by leasing their fiber – but IP costs less to provide than copper/facilities/equipment-energy-heavy and expensive-to-maintain PSTN. 

For example, AT&T offers MPLS-enabled IP VPNs, allowing use of a single network to support their voice, data and other business applications. VPN traffic can be prioritized using CoS so a single VPN can support all applications, including VoIP.

Verizon’s Verizon IP Trunking services offer a native SIP trunk directly to IP PBXs; Verizon IP Integrated Access leverages gateway devices that interface with PBXs and key systems. Contact centers can obtain network efficiencies such as sharing trunking resources for multiple centers with Verizon’s Burstable Enterprise Shared Trunking feature. Enhanced IP-based failover solutions from the carrier ensure business continuity, and reliability and performance.

“The incumbent carriers are definitely in on this,” says Koniecki. “They have finally come around to realize that SIP is the future.”

Carriers have been attempting to employ the same kinds of complex pricing and tariffs for SIP as they used in PSTN. But Imeish and Koniecki are now seeing them back off in the face of competition.

When buying carrier services Koniecki and Imeish recommend performing thorough quality and pricing due diligence and from this menu selecting one possibly two suppliers, then split the traffic between them to keep them competitive and redundant. Also to own their own SBCs, which makes it easier for firms to switch SIP carriers, use other ones and provision SIP trunks.

To monitor carrier costs contact centers should take a second look at telecom expense management and broaden its scope from traditional landlines to WANs and to wireless. This method can pay off in spades. Dimension Data did one such analysis for a large hospital and it found that the client was paying for a multimegabyte Internet circuit that was three to four times more than they could pay for it from anywhere else.

“As long as carriers have interesting ways of presenting bills there will always be a need to have someone who can decode and analyze the bills for potential savings and adherence to policy,” says Imeish. 

Navon recommends doing test calls, considering redundancy/failover options so that your phones will always be up – this is a great feature of VoIP—and ensure that the broadband connection has the needed QoS. Also, avoid signing any long-term contracts, because the service should sell itself. Optimized Business’s subsidiary provides no term or volume commitments or per-trunk fees as well as cost savings.

“My advice is to enjoy the overall flexibility of VoIP,” says Navon.

Ensuring IP Quality Inside the Contact Centers

IP voice quality concerns do not end when the calls arrive at the routers or leave the premises via the carriers. There can be just as many if not more issues such as with jitter and latency inside the contact centers on their LANs.

The internal quality challenges arise from bandwidth competition from data, reports Jeff Betteker, COO of One Source Networks. Services are delivered across a common port and data connection. And there is usually no QoS - which is commonly available on WANs – to prioritize the voice traffic.

“To preserve quality, it’s essential to evaluate the data environment and determine if the router supports QoS, ensuring that prioritization is set correctly,” recommends Betteker. “For example, when we deliver IP voice equipment to our clients, we provide an IP phone that offers QoS to consistently guarantee quality. “


There can still be potential IP/SIP quality issues when connecting with home-based agents, though these are lessening as both bandwidth and availability increase as carriers compete intensively for residential and small office/home office customers including for IPTV (News - Alert).

Yet the contention point is not much on the residential street pipes whether cable or DSL or wireless anymore but inside the agents’ premises. Jim Koniecki, technical consultant of unified communications and collaboration for Dimension Data, points out agents may purchase bare minimum bandwidth without taking into account other users.

He and his colleague Lawrence Imeish, principal consultant at Dimension Data, advise that contact centers require – and enforce – an acceptable use policy and monitor their home agents to obtain high bandwidth connections and separate IP (or PSTN) lines. Or employ routers that segregate business from recreation traffic.

One Source Networks often recommends that the home agents utilize a secure tunnel from the users’ PC back to the carriers’ routers that allows a consistent flow of data, regardless of peering points and type of IP connections.

“Preservation of quality for remote and home workers that utilize consumer-grade Internet is a constant challenge,” says Jeff Betteker, COO of One Source Networks.



Broadvox (News - Alert)

Dimension Data


One Source Networks

Optimized Business



Brendan B. Read is TMCnet’s Senior Contributing Editor. To read more of Brendan’s articles, please visit his columnist page.