Definitive MPLS Network Designs [Electronic resources] نسخه متنی

Design Lessons to Be Taken from Telecom Kingland

A number of conclusions can be drawn from Telecom Kingland's design:

An IP/MPLS packet core can be used as the multiservice core to integrate current and future services (including Internet, Layer 3 VPN, enterprise voice within a Layer 3 VPN, PSTN telephony trunking, and so on).

Multiple services may be offered by the same edge devices, although extra consideration is necessary in terms of security and scale.

Load balancing of Layer 3 MPLS VPN traffic can be achieved through the combination of iBGP Multipath functionality and different route distinguishers per VRF.

Carrier's Carrier may be used as an effective tool to help scale large routing requirements, or for customers that require service separation within their own network environments.

PSTN telephony trunking can be carried over the packet core with extremely strict QoS and resiliency both during normal situations and upon link/SRLG/node failure. This involves a tight combination of a dedicated, strict priority queue and the call admission control, Constraint-Based Routing, and Fast Reroute capabilities of MPLS Traffic Engineering.

Internet and Layer 3 MPLS VPN traffic can be efficiently rerouted in case of link, SRLG, or node failure within a few seconds in the worst case with an appropriate OSPF design.

Multiple CoS on access links is very useful for multimedia VPN. This involves sophisticated QoS service policies and requires careful fine-tuning (particularly on lower-speed links).

Where capacity can be easily and economically provisioned, multiple CoSs can be handled together as a single class in the core (all the VPN CoSs plus the Internet in TK's case). Appropriate levels of QoS can be ensured via capacity planning. However, it's a good idea to isolate essential control traffic (routing, signaling, management) to protect network stability even in the worst, unexpected situations.

IPv6 Internet services can be offered in an incremental fashion over an existing MPLS core without any upgrade or change in the core and thus without any impact on existing services.