I was afforded today a brief overview of Packet Design’s software products in the areas of capacity planning and traffic engineering on IP networks.
I can’t provide a complete review of the capabilities of their product since it is quite comprehensive, but I can comment on the aspects that were presented to me which may have particular interest to those seeking a tool to assist in packet network traffic engineering.
Packet Design’s Route Explorer appliance is a routing protocol modelling tool. To model the network’s IGP, it acts as a fully-fledged OSPF or IS-IS speaker that is attached directly into the network via the closest backbone router. Through this interface, it passively observes the link state advertisements that occur within the IGP protocol and it is able to create a replica topology map that shows which devices are connected and by which links. This can be visualised on a GUI.
This allows an engineer to quickly query internal routes and answer questions related to which links are used to satisfy which routes on the network without actually touching the network. An engineer can also assess the impact of works activities or the benefits of proposed topology changes by artificially manipulating the IGP topology in terms of links or link metrics and Route Explorer will show the resulting effects on routing decisions.
In addition to IGP simulation, Route Explorer can also speak IBGP to backbone routers on the network in order to glean information about the external networks to which one is connected. This effectively extends the “what-if” route look-ups possible within the IGP to include all exterior Internet routes which is very powerful. Such capability allows one to assess the network routing effects associated with connecting a new customer, or losing a customer.
Route Explorer capacity is dimensioned based upon the route count that one expects to feed the devices for modelling and it would appear to be capable of supporting split-AS routing policies where one part of the network may have a slightly different view of the best exit than another.
The Traffic Explorer appliance complements Route Explorer by collecting Netflow accounting records from router platforms and mapping them onto the topology discovered by Route Explorer in order to compute the estimated usage on a per-link basis. The general recommendation is to enable Netflow accounting in a sampled mode on all external interfaces so that traffic entering and leaving the autonomous system is observed by the Traffic Explorer platform but not repeatedly counted.
As well as offering a near-realtime view on link usage that is independent of SNMP interface meters, Traffic Explorer extends the usefulness of Route Explorer since the “what-if” scenarios that can be conceived can also include the resulting traffic swing which is an extremely attractive feature for impact analysis or new or upgraded circuit planning.
Traffic Explorer is dimensioned by the rate of receipt of Netflow accounting records and both Traffic Explorer and Route Explorer are licensed by appliance. This is an attractive feature since in most cases it means license fees are proportional to traffic and hopefully revenue. Competing products in this area often license in terms of the raw network element count, irrespective of actual traffic levels, which can punish resilient network design.
Packet Design’s portfolio also includes an MPLS VPN Explorer capability which makes use of MPLS-based Netflow and multi-protocol BGP in order to report on VPN-specific routing and traffic.
User access to both Route Explorer and Traffic Explorer is through X11 or VNC to a visualisation server which abstracts the details of the individual collector elements needed to create the view. The X11/VNC access is a slight disappointment, in my opinion, since one would think that a native client with specific client/server protocl would probably perform better, especially on geographically-diverse networks where a central server is unlikely to be in the same place as the user.
In summary, the Packet Design solution appears to be a promising addition to a network looking to enrich its view of routing and traffic analysis.