BGP4 Network - Router Hardware

Summary

For Autonomous Routing a router is required which supports the BGP4 protocol. The router is the gateway between the internal network and the external global Internet, and hides internal routing policies from the outside world.

BGP4 routers can be classified based on technology and performance. Which class is advisable depends on customer specific performance and availability requirements. Pricing is largely defined by the router class. In most cases money can be saved by using refurbished router(s).

A refurbished CAM Cache-class router (Foundry BigIron) with up to 32 Gbit/s performance starts at € 5.545,-.

Description

Which router to choose?

Which specific brand and type router is most suited depends on the specific type of use, performance and redundancy requirements, budget, etc. and can only be determined on a case-by-case basis. The classification made below can help gaining insight on the options.

Router classes

Below different router classes are described briefly including specific advantages and vulnerabilities of each class:

100% CAM Router

Routers in this class have enough Content Addressable Memory (CAM - see also Wikipedia on this type of memory in routers) on each of their interface blades to contain and preload all Internet destinations (full routing table) in advance.

Advantages: Each arriving packet can be forwarded by the interface blades in (ASIC or FPGA) hardware using the CAM, without consulting the central CPU. This behavior makes wirespeed performance at any packet size and packet rate (packets per second) possible, regardless of the source/destination address of the packet.

Vulnerabilities: With the growing Internet routing table, optional implementation of IPv6 on the same router, large layer2 or layer4 switching tables, and use of trunking/multipath, total CAM usage will grow. Theoretically CAM might eventually exhaust, effectively downgrading the router to a CAM Cache class router as described below.

CAM Cache Router

This type of router uses CAM on each interface blade in order to be able to forward traffic in hardware. The CAM size is not large enough to contain/prepopulate it with the full Internet routing table.

Advantages: When there is traffic for/from an Internet destination (flow), upon the first packet it is looked up in memory (CPU), and then programmed in the CAM. Following packets with the same source/destination (same flow) can then be handled in hardware (wirespeed). So the CAM functions like a cache, speeding up the handling of the second and following packets to wirespeed for existing flows.

Vulnerabilities: If the CAM is full, old destinations are removed from it by the CPU before programming new entries. With traffic for/from many different destinations (e.g. DDOS attacks with spoofed source addresses) both the CAM and CPU can easily be exhausted due to handling all the CAM cache misses, making room in the CAM by removing old entries, and programming new entries. During exhaustion, packet loss can occur.

Further certain traffic types sometimes cannot be programmed in hardware or services cannot be provided in hardware and still need to be handled in CPU (e.g. broadcast, multicast, rate limits, statistics), making it more vulnerable for exhaustion.

Appliance Router

An appliance in this context is a router based largely on standard PC hardware components, running a custom and integrated real time OS and routing software and generally handling all traffic in a central CPU.

Advantages: In comparison to software routers, in a router appliance, hardware, OS and routing software are tightly integrated and the OS has specifically been designed and build for this purpose (just like in CAM-based routers). Most importantly this provides more stability.

Vulnerabilities: The disadvantage of an appliance router is that its performance is largely limited by the performance of the central CPU in terms of packets per second it can handle. It can generally not provide wirespeed performance on all ports, especially with small packet sizes. It is especially vulnerable to DDOS attacks with small packets.

Software Router

A software router is completely based on standard PC hardware, and an open source Operating System (e.g. Linux, BSD) and open source routing software (e.g. Quagga).

Advantages: The main advantages of software routers is their low cost. Because of this very fast and modern CPU's and abundant system memory can be used. Compared to appliance routers this results in relatively higher performance (in terms of packets per second) and the practical absence of system memory limitations. Software routers offer the same type of redundancy features (VRRP) as the other router classes.

Vulnerabilities: A disadvantage of software routers is the less tight integration of hardware, OS and routing software, resulting in less stability. Software routers are also limited in performance by the central CPU, although generally the performance is a little better then appliance routers.

Redundancy

For a Non-Stop redundant setup two routers are required. They can be used either in a load sharing or in a primary/backup (hot standby) configuration.

New or refurbished

An alternative for expensive new BGP4 routers is the use of refurbished routers. Refurbished routers are used routers, which have completely been tested, cleaned and updated, so they are ready for a second life.

BGP4 routers are generally designed for a very long and stable life. They are mostly not replaced because they don't work anymore, but because faster routers, routers with more or different interfaces or with different features are needed. That means that the use of refurbished routers generally do not impose a substantial stability or loss risk. A redundant setup, with two routers, reduces any possible risk even further.

Pricing

Open Peering only offers new BGP4 router hardware in all-in turn-key projects, based on custom offers. Open Peering does however offer refurbished BGP4 routers:

Refurbished Foundry BigIron

Open Peering
BGP4 Router Hardware
Refurbished Foundry BigIron***
One-off	€ 5.545,-

The Foundry BigIron is a CAM Cache chassis-based BGP4 router which was designed and build for carrier class redundancy and aimed at 1 Gbit/s connections (up to 32) over fiber (GBIC, SFP or fixed) and 100 Mbit/s UTP ports with wirespeed handling under normal circumstances (normal flows). The router has proved itself in many networks and is considered very stable.

Have a look at the BigIron specifications.

Refurbished Foundry MG8

Open Peering
BGP4 Router Hardware
Refurbished Foundry MG8****
One-off	€ 15.690,-

The Foundry MG8 is a very recent CAM Cache chassis-based BGP4 router primarily aimed at wirespeed 10 Gbit/s connections under normal circumstances (normal flows).

Have a look at the MG8's specifications.

Hardware support and replacement contract

On all refurbished Foundry equipment supplied, Open Peering offers a hardware replacement service. In the tariff of this service it is taken into account that the equipment is not new, and does not fall under manufacturer support.

The monthly costs for such service are calculated as percentage of the total refurbished prices of the equipment, and depends on the type of network setup: non-redundant with one router or fully Non-Stop redundant with two routers. Further the services hours (offices hours or 24*7) and responce time (next-business-day or max 4 hours) influence the cost.

Conditions

Delivery time

The delivery time (other then under a hardware replacement contract) is (if all parts are in stock) generally max 10 working days.

Guarantee

All equipment is delivered with a three months hardware guarantee. With the hardware no guarantee or support is provided on the OS (firmware). It is possible to get a official software support contract for refurbished Foundry hardware directly from Foundry resellers.

Excluding transport

To keep costs low, pricing (other then under a hardware replacement service) is based on customer-pickup from the Open Peering NOC in The Hague or customer-payed courier-pickup.