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95 lines
4.8 KiB
Markdown
95 lines
4.8 KiB
Markdown
# Introduction
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Building a BNG from scratch requires a lot of testing but commercial BNG test software
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is often very expensive, resource intensive and provide a lot of administrative overhead
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to maintain such.
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Therefore we decided to build our own BNG test solution which is completely build from scratch
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targeted for max scaling with small resource footprint, simple to use and easy to integrate in
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our test automation infrastructure.
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The BNG Blaster is able to simulate more than hundred thousand PPPoE subscribers including IPTV,
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traffic verification and convergence testing capabilities.
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* *High Scaling:* > 100K sessions
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* *Low CPU and Memory Footprint:* < 100MB memory for 16K sessions
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* *Portable:* runs on every modern linux, virtual machines and containers
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* *User Space:* all protocols implemented in user-space from scratch and optimized for performance
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* *IPTV:* IGMP version 1, 2 and 3 with automated channel zapping test
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* *Automation:* the BNG Blaster Controller provides an automation friendly REST API and robot keywords
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```
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$ bngblaster --help
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____ __ ____ _ __ ,/
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/ __ \ / /_ / __ ) _____ (_)_____ / /__ ,'/
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/ /_/ // __// __ |/ ___// // ___// //_/ ,' /
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/ _, _// /_ / /_/ // / / // /__ / ,< ,' /_____,
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/_/ |_| \__//_____//_/ /_/ \___//_/|_| .'____ ,'
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____ _ _ ______ ____ _ _ / ,'
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/ __ ) / | / // ____/ / __ ) / /____ _ _____ / /_ ___ ____ / ,'
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/ __ |/ |/ // / __ / __ |/ // __ `// ___// __// _ \ / ___/ /,'
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/ /_/ // /| // /_/ / / /_/ // // /_/ /(__ )/ /_ / __// / /
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/_____//_/ |_/ \____/ /_____//_/ \__,_//____/ \__/ \___//_/
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Usage: bngblaster [OPTIONS]
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-h --help
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-C --config <args>
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-l --logging error|igmp|io|lcp|ncp|normal|pcap|timer|timer-detail|ip
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-L --log-file <args>
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-a --access-interface <args>
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-n --network-interface <args>
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-u --username <args>
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-p --password <args>
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-P --pcap-capture <args>
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-J --json-report <args>
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-c --pppoe-session-count <args>
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-g --mc-group <args>
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-s --mc-source <args>
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-r --mc-group-count <args>
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-z --mc-zapping-interval <args>
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-S --control socket (UDS) <args>
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-I --interactive (ncurses)
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```
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The BNG Blaster includes an optional interactive mode (`-I`) with realtime stats and
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log viewer as shown below.
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## Theory Of Operation
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The BNG Blaster has been completely built from scratch, including user-space implementations of the entire protocol
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stack you need for interfacing with a BNG. It’s core is based on a very simple event loop which serves timers and signals.
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The timers have been built using a constant time (O(1)) library which we built purposely to start, restart and delete the
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protocol session FSM timers quickly and at scale.
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BNG Blaster expects a Linux kernel interface which is up, but not configured with any IP addresses or VLAN as it expects to
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receive and transmit raw ethernet packets.
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BNG Blaster does I/O using high-speed polling timers using the so-called PACKET_RX_RING/PACKET_TX_RING abstraction where a
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userspace program gets a fast-lane into reading and writing to kernel interfaces using a shared ring buffer. The shared ring
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buffer is a memory mapped "window" that is shared between kernel and user-space. This low overhead abstraction allows to
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transmit and receive traffic without doing expensive system calls.
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Sending and transmitting traffic is as easy as just by copying a packet into a buffer and setting a flag. This is super
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efficient and hence we have measured the I/O performance of roughly 1M pps per single CPU thread, which is more than enough for
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our purposes here.
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BNG Blasters primary design goal is to simulate thousands of subscriber CPE's with a small hardware resource footprint. Simple
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to use and easy to integrate in our robot test automation infrastructure. This allows to simulate more than hundred thousand
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PPPoE subscribers including IPTV, traffic verification and convergence testing from a single medium scale virtual machine or to
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run the blaster directly from a laptop.
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The BNG Blaster provides two types of interfaces. The first interface is called the access interface which emulates the PPPoE
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sessions. The second interface-type is called network interface. This is used for emulating the core-facing side of the
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internet.
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This allows to verify IP reachability by sending bidirectional traffic between all PPPoE sessions on access-interface and the
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network interface. The network interface is also used to inject downstream multicast test traffic for IPTV tests.
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