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diff --git a/docs/vCGNAPT/README.rst b/docs/vCGNAPT/README.rst new file mode 100644 index 00000000..eda94831 --- /dev/null +++ b/docs/vCGNAPT/README.rst @@ -0,0 +1,189 @@ +.. this work is licensed under a creative commons attribution 4.0 international +.. license. +.. http://creativecommons.org/licenses/by/4.0 +.. (c) opnfv, national center of scientific research "demokritos" and others. + +======================================================== +Carrier Grade Network Address Port Translation - vCGNAPT +======================================================== + +1 Introduction +============== +This application implements vCGNAPT. The idea of vCGNAPT is to extend the life of +the service providers IPv4 network infrastructure and mitigate IPv4 address +exhaustion by using address and port translation in large scale. It processes the +traffic in both the directions. + +It also supports the connectivity between the IPv6 access network to IPv4 data network +using the IPv6 to IPv4 address translation and vice versa. + +About DPDK +---------- +The DPDK IP Pipeline Framework provides set of libraries to build a pipeline +application. In this document, CG-NAT application will be explained with its +own building blocks. + +This document assumes the reader possess the knowledge of DPDK concepts and IP +Pipeline Framework. For more details, read DPDK Getting Started Guide, DPDK +Programmers Guide, DPDK Sample Applications Guide. + +2. Scope +========== +This application provides a standalone DPDK based high performance vCGNAPT +Virtual Network Function implementation. + +3. Features +=========== +The vCGNAPT VNF currently supports the following functionality: + • Static NAT + • Dynamic NAT + • Static NAPT + • Dynamic NAPT + • ARP (request, response, gratuitous) + • ICMP (terminal echo, echo response, passthrough) + • ICMPv6 and ND (Neighbor Discovery) + • UDP, TCP and ICMP protocol passthrough + • Multithread support + • Multiple physical port support + • Limiting max ports per client + • Limiting max clients per public IP address + • Live Session tracking to NAT flow + • NAT64 + • PCP Support + • ALG SIP + • ALG FTP + +4. High Level Design +==================== +The Upstream path defines the traffic from Private to Public and the downstream +path defines the traffic from Public to Private. The vCGNAPT has same set of +components to process Upstream and Downstream traffic. + +In vCGNAPT application, each component is constructed as IP Pipeline framework. +It includes Master pipeline component, load balancer pipeline component and vCGNAPT +pipeline component. + +A Pipeline framework is collection of input ports, table(s), output ports and +actions (functions). In vCGNAPT pipeline, main sub components are the Inport function +handler, Table and Table function handler. vCGNAPT rules will be configured in the +table which translates egress and ingress traffic according to physical port +information from which side packet is arrived. The actions can be forwarding to the +output port (either egress or ingress) or to drop the packet. + +vCGNAPT Graphical Overview +========================== +The idea of vCGNAPT is to extend the life of the service providers IPv4 network infrastructure +and mitigate IPv4 address exhaustion by using address and port translation in large scale. +It processes the traffic in both the directions. + +.. code-block:: console + +------------------+ + | +-----+ + | Private consumer | CPE |---------------+ + | IPv4 traffic +-----+ | + +------------------+ | + +------------------+ v +----------------+ + | | +------------+ | | + | Private IPv4 | | vCGNAPT | | Public | + | access network | | NAT44 | | IPv4 traffic | + | | +------------+ | | + +------------------+ | +----------------+ + +------------------+ | + | +-----+ | + | Private consumer| CPE |-----------------+ + | IPv4 traffic +-----+ + +------------------+ + Figure 1: vCGNAPT deployment in Service provider network + + +Components of vCGNAPT +===================== +In vCGNAPT, each component is constructed as a packet framework. It includes Master pipeline +component, driver, load balancer pipeline component and vCGNAPT worker pipeline component. A +pipeline framework is a collection of input ports, table(s), output ports and actions +(functions). + +Receive and transmit driver +---------------------------- +Packets will be received in bulk and provided to load balancer thread. The transmit takes +packets from worker thread in a dedicated ring and sent to the hardware queue. + +ARPICMP pipeline +------------------------ +ARPICMP pipeline is responsible for handling all l2l3 arp related packets. + +---------------- +This component does not process any packets and should configure with Core 0, +to save cores for other components which processes traffic. The component +is responsible for: + 1. Initializing each component of the Pipeline application in different threads + 2. Providing CLI shell for the user + 3. Propagating the commands from user to the corresponding components. + 4. ARP and ICMP are handled here. + +Load Balancer pipeline +------------------------ +Load balancer is part of the Multi-Threaded CGMAPT release which distributes +the flows to Multiple ACL worker threads. + +Distributes traffic based on the 2 or 5 tuple (source address, source port, +destination address, destination port and protocol) applying an XOR logic +distributing the load to active worker threads, thereby maintaining an +affinity of flows to worker threads. + +Tuple can be modified/configured using configuration file + +4. vCGNAPT - Static +==================== +The vCGNAPT component performs translation of private IP & port to public IP & +port at egress side and public IP & port to private IP & port at Ingress side +based on the NAT rules added to the pipeline Hash table. The NAT rules are +added to the Hash table via user commands. The packets that have a matching +egress key or ingress key in the NAT table will be processed to change IP & +port and will be forwarded to the output port. The packets that do not have a +match will be taken a default action. The default action may result in drop of +the packets. + +5. vCGNAPT- Dynamic +=================== +The vCGNAPT component performs translation of private IP & port to public IP & port +at egress side and public IP & port to private IP & port at Ingress side based on the +NAT rules added to the pipeline Hash table. Dynamic nature of vCGNAPT refers to the +addition of NAT entries in the Hash table dynamically when new packet arrives. The NAT +rules will be added to the Hash table automatically when there is no matching entry in +the table and the packet is circulated through software queue. The packets that have a +matching egress key or ingress key in the NAT table will be processed to change IP & +port and will be forwarded to the output port defined in the entry. + +Dynamic vCGNAPT acts as static one too, we can do NAT entries statically. Static NAT +entries port range must not conflict to dynamic NAT port range. + +vCGNAPT Static Topology: +------------------------ +:: + IXIA(Port 0)-->(Port 0)VNF(Port 1)-->(Port 1) IXIA + operation: + Egress --> The packets sent out from ixia(port 0) will be CGNAPTed to ixia(port 1). + Igress --> The packets sent out from ixia(port 1) will be CGNAPTed to ixia(port 0). + +vCGNAPT Dynamic Topology (L4REPLAY): +------------------------------------ +:: + IXIA(Port 0)-->(Port 0)VNF(Port 1)-->(Port 0)L4REPLAY + operation: + Egress --> The packets sent out from ixia will be CGNAPTed to L3FWD/L4REPLAY. + Ingress --> The L4REPLAY upon reception of packets (Private to Public Network), + will immediately replay back the traffic to IXIA interface. (Pub -->Priv). + +How to run L4Replay: +-------------------- +:: + 1. After the installation of samplevnf: + go to <samplevnf/VNFs/L4Replay> + 2. ./buid/L4replay -c core_mask -n no_of_channels(let it be as 2) -- -p PORT_MASK --config="(port,queue,lcore)" + eg: ./L4replay -c 0xf -n 4 -- -p 0x3 --config="(0,0,1)" + +6. Installation, Compile and Execution +----------------------------------------------------------------- +Plase refer to <samplevnf>/docs/vCGNAPT/INSTALL.rst for installation, configuration, compilation +and execution. |