Tata Internet Services, which offers its services under the Tata Indicom brand, is one of the few service providers in the country that is offering IP VPN services in India. Prasoon Srivastava, GM (infrastructure solutions group), TISL, spoke to Voice&Data on IP VPN and its benefits for corporates. Excerpts:

Is IP VPN better than layer 2 VPN?
Layer-3 VPNs are known to us more as IP VPNs, and are rated high on scale of flexibility. An IP-VPN link can be set up anywhere in the world between two end points, with the network automatically handling the traffic routing.

Layer2 VPN is identified more with point to point circuits (permanent virtual circuit in frame relay) and hence is considered relatively more secure with a committed data throughput, both of which are present by virtue of these links being point to point. However, Layer2 VPNs do not offer the flexibility offered by Layer3 VPNs.

For most of service providers offering VPNs, both Layer2 and Layer3 are important.

Are carrier networks in India fit for IP VPN?
Yes, and we are providing IPSec MPLS VPN services to mission-critical customers in almost every vertical by using the infrastructure of long-distance service providers.

How does MPLS facilitate IP-based VPNs?
IP MPLS VPN is the best mix of Layer 2 and Layer 3. MPLS VPNs is globally acknowledged by many (including Cisco and Juniper) to be the most secure, fast and next-generation VPN technology. One of the features in MPLS that contributes to its speed and security is that there is a unique label (and hence cannot be spoofed unlike IP header) for every packet transmitted. This label is checked only at the service provider edge routers unlike IP header analysis happening at every hop which made an IP VPN relatively less secure and also slower.

IPsec over MPLS would therefore offer layered security and is acknowledged by many service providers worldwide to be the most secure VPN option in data transmission today.

The potential customers for IPSec MPLS VPNs...
These would be mission- and business-critical networks like banking and finance. In these verticals, flexibility is often compromised for more security. This is why they opt for fixed point-to-point CUG networks. With the advent of net banking and other Internet-based applications, the flexibility offered by IP can no longer be ignored. We have been quite successful with our IPSec MPLS offering. We have acquired VPN orders from large number of BFSI customers including three well known banks in 2002 .In addition, we have acquired large customer base for mission critical network deployments in other verticals like manufacturing, process and retail, and media.

What are the advantages of IP VPN over frame relay or ATM?
One of the features in MPLS which contributes to its speed and security is that in MPLS there is a unique label (hence cannot be spoofed unlike IP header) for every packet transmitted. This label is checked only at the service provider edge routers unlike IP header analysis happening at every hop which made an IP VPN relatively less secure and also slower.

For integrated video, voice and data applications, the use of MPLS helps to guarantee differential QoS (quality of service) levels for multi-service deployments by way of packet prioritization/bandwidth reservation required by voice/video. The use of IP for video, voice and data is a key enabler for easy integration of voice/video calls into customer’s application thereby bringing down the overall TCO for large and complex enterprise deployments.

Ravi Shekhar Pandey