When the need for increased bandwidth and improved Quality of Service (QoS) at reduced cost drove Kodak to transition its network from leased lines and frame relay to MPLS VPNs, the company was able to meet its goals by closely supervising and cooperating with its ISPs and maintaining the final responsibility for meeting business data needs with the network staff. Kodak's experiences investigating available services, working with the chosen suppliers, and transitioning to the new network can provide sound direction for others transitioning to an MPLS VPN.
Among the reasons for Kodak's network overhaul were the consolidation of SAP usage to one instance in Rochester, NY and the introduction of VoIP to reduce cost. Both SAP and VoIP create requirements for consistent bandwidth and minimal network delay. MPLS provides these QoS guarantees at a lower cost than frame relay or leased lines.
The first roadblock to Kodak's VPN implementation was that their domestic and international operations required multiple VPNs and no single supplier could provide the geographical coverage. The company learned that some ISPs claim to cover an entire geographical area, but do so through sub-suppliers that require separate agreements.
Dealing with separate suppliers created a whole new obstacle. There proved to be little standardization of Class of Service (CoS) offerings from different providers. Thomas J. Steele, Global Telecom Manager at Kodak explained, "VPNs are still new, so there are no standards regarding service levels, CoS, or other VPN features. Thus, each supplier's offering must be analyzed in detail to fully understand what is being purchased."
Even after you have a good understanding of what each supplier is offering it still pays to keep close track of your network usage, as Kodak discovered. Usage changes constantly as applications are added or removed, so actual traffic levels must be compared regularly against contracted amounts. "We pay more for 'business class' CoS than for 'Best Effort', says Steele. "If 'Business Class' is being under-utilized, then maybe we should shift more of the access bandwidth to "Best Effort".
Even after suppliers were identified, Kodak encountered a myriad of problems integrating their systems and requirements with what the ISPs were offering.
Kodak engineers needed to review the configuration of suppliers' CERs (Customer Edge Routers) regularly to ensure maximum performance. Also, Kodak's network management systems needed read access to CER SNMP parameters for link utilization, errors, CPU utilization, memory and latency to construct a unified view of the entire network.
Another issue was that VoIP reports provided by suppliers are very rudimentary. Kodak requires RADIUS accounting records from the VoIP gateway routers. Reports on call completions and failures and on Cisco voice quality scores can be created from these records. Several suppliers still cannot supply them.
Other problems occurred when a single supplier supported more than one of Kodak's VPNs. BGP prevents loops by preventing traffic from traversing the same AS (autonomous system) more than once, which prevented traffic flow from one Kodak VPN to another. The proposed solution, to create a default route, was undesirable because it did not provide an alternate route. But no other practical solution was available.
"It's been our experience that the supplier simply does not understand the nuances of an enterprise network, especially when there are complex backup scenarios, and preferred traffic routing paths which come into play where the supplier VPN connects to the rest of the network." says Steele.
Suppliers may claim the ability to handle all of a network's design, but the expertise of Kodak's engineers and their knowledge of Kodak's network was critical for a successful implementation. They worked closely with the supplier's engineers to ensure correct latency on critical paths making sure the supplier provided multiple links from key sites to the supplier network and that the links connected to diverse sites on the supplier network. Kodak engineers also worked closely with the supplier to plan and coordinate the switchover from the old network.
Finally, use of MPLS VPNs did not eliminate the responsibility of Kodak's network staff. Steele explains, "In the 'old' days, the supplier only provided a layer 1/2 transport network. They are now determining how traffic will flow across those networks. We (Kodak) still bear the responsibility to insure proper and optimal routing across our enterprise."
David B. Jacobs has more than twenty years of networking industry experience. He has managed leading-edge software development projects and consulted to Fortune 500 companies as well as software start-ups.
