Return on Investment (RoI) is the most crucial factor as far as telecom spending on routers is concerned. With finance limited and rollout requirements massive, operators want to get full value out of every penny spent. RoI from routers are being looked at in terms of routers’ basic routing performance and the ability to support various services without taxing the performance of the network. Not only the capex has to be the main concern, service providers have to pay attention to opex as well. The hidden costs can be the biggest headache when it comes to technology expenses. Some of the RoI issues that should come up during a router purchase are: What is the price of bringing in more redundancy in the network? What are the expenses involved in memory upgrades? What are the licences attached to feature additions?

Buying Tips

n Stability: When it comes to routers in the context of a telco, this is the most important aspect. In a live public network, the best of routers are really tested. The quality of Internet services and other packet services is a function of how routers on the operator’s network perform. This selection criteria is certainly going to become all the more crucial in router purchase as operators look forward to differentiate their services through better quality of services, differential grades of services, managed packet services such as MPLS-based VPNs. As more customers demand service level agreements, network faults and downtimes are not being tolerated. This means that service providers have to see that the routers that form the backbone of the network are not down and if they are down, there is a backup. Backups are costly. So, redundancy should be built into the router that is implemented. The router must be highly available with hitless fail over, port redundancy and module redundancy. Nowadays, routers that separate the routing and forwarding functionalities are in demand as this reduces the risk of downtimes. The router should be able to handle unstable network conditions such as sudden surge in bandwidth usage, route bottlenecks, etc. Also, it should be capable of handling denial of service (DOS) attacks.

n Reliability: Look for reliability at all levels: box level, node level and link level. The product should be able to turn on service without degrading the performance of the network. MPLS-capability is a must at the core of the network—ensure the routers are capable of MPLS. The router should be able to give line rate performance. The same line card should be able to single-handedly turn on a variety of services.

n Scalability: One needs to check out the number of routes that can be handled, and the number of VPNs that can be supported. Port density (physical and logical) is an important criterion. The router should be able to support very hi-bandwidths viz STM16 and STM64, etc. And the router should be able to support as many of them from a single box.

n Modularity: An idle link is inventory for service providers. So, adding network capacity as you grow is a preferred practice. While adding resources, capability to do online insertion and removal of modules is a great feature as you don’t have to turn off a router to upgrade it. This is essential, telecom being a 24x7 sector. Also, one must ensure the router has support for a range of interfaces, so that there can be and mix n match of interfaces.

n Features: This is the factor that will decide how your services will be different from others. It is not only important that the router supports as many features as possible, it must also boast of those features that really helps in building value to the services. Some features that ought to be looked for are L3 VPNs, L2 VPNs (Ethernet over MPLS, Frame Relay over MPLS, ATM over MPLS, PPP over MPLS, HDLC over MPLS), VPLS, IPSec encryption, QoS (differentiated services), customer self provisioning, etc.

n Benchmarks: Just as you meticulously planned your network’s configuration as a whole, you should give close scrutiny to what you want your routers to do and where you expect them to do it. There will be a premium to be paid if 99.999 is to be enabled. It’s a tradeoff between price and quality of service.

Few real standards exist for routers. This lack of a solid means of comparison of competing devices, added to the continually growing role that routers play in allowing dissimilar networks to communicate, makes router modeling even more important. When you consider the cost of networking hardware and the investment of time that installing and fine-tuning it represents, having a reasonable idea up-front of how routers can be expected to perform in your environment is practically critical.

Benchmarks that can be referred to are of two types—commercial and technical.

n Commercial
Case Studies: Look at successful implementation of routers by similar service providers. Here, the vendors and integrators would play a major role. Most companies maintain a dossier of case studies for reference. Get deeper information about the previous cases.

Look Beyond Price: Price should not be the ultimate decider. A reliable router makes up for the premium paid in no time. On the other hand, a cheaper unreliable router can become a major bottleneck. If the requirement parameters are not taken care of, the final spend becomes more than the premium that would have been paid in the first hand.

n Technical
Standards: See that the routers meet the compliance parameters set by Bellcore. Network equipment building system (NEBS) GR-63 and GR-1089 have been the de facto benchmarks for the industry for more than two decades. They have been used to verify that products are truly carrier-class, installation-ready, and equipment compatible. Compliance to these test parameters of Bellcore demonstrates that the equipment has been thoroughly tested for safety and functional criteria for use in telecommunications networks. Also, check the products against standards required or developed by organizations such as the FCC, CISPR, IEC, IEEE, ASTM, ANSI, and ETSI.

Independent Tests: Check out the currently done router tests by independent labs like Light Reading (www.lightreading.com ) and Tolly Group (www.tolly.com).

First-hand Testing: Doing a first-hand test is extremely critical. Router testers are available from test and measurement companies like Agilent, which can generate routers and instability in test beds. Customers can also test products at vendors’ premises.