National Internet Exchange Of Afghanistan (NIXA)



As the Internet grows in size, number of users, and usage, Internet Service Providers (ISPs) continue to exchange increasing amounts of data traffic. A basic underpinning of the Internet are points where inter-ISP traffic can be exchanged. These interconnection points are called Network Access Points (NAPs) or Exchange Points (EPs). To help cope with the ever increasing amount of Internet traffic, many new Exchange Points have been deployed, and growth in use of existing EPs has increased. This trend is expected to continue as it seems to directly support the growth of the local and regional ISP industry, allowing local traffic exchange and reduced dependency on the large, established ISPs.


Large ISPs are relying on alternative private, or direct, interconnection to support peering and exchange of traffic at critical locations. Interconnect policies depend on business agreements, service level agreements, economies of scale, provider size and value, and regional and world telecommunications circuit costs. In addition, as Business customers are placing their mission critical applications on the Internet, some industries are demanding and are willing to pay for guaranteed quality of service (QoS). EP-based services such as router and server collocation, carrier access, remote management, and physical layer interconnection have proven to be important functions for Internet providers.


NAP and EP characteristics


Exchange points are defined as multiple-access networks allowing ISPs to exchange traffic and routing information with other ISPs. Multiple-access networks support the potential for any to any communication and are typically built from traditional switched technologies, like Ethernet, FDDI, and ATM. The basic premise of an Exchange Point is that parties can purchase a connection to this location and gain the ability to exchange traffic with others at the exchange point. An analogy to this model would be a major hub airport in which several different airlines are served. At that airport, the airlines can exchange passengers between their flights in much the same way that ISPs can exchange IP packets across the EP.



Internet service providers (ISPs) and other organizations which connect their networks at an Internet exchange point (IXP) benefit from cheaper local bandwidth, faster local access, improved resilience, co-ordinated engineering and a reduction in transit and infrastructure costs.


IXPs allow ISPs to exchange their traffic - so an email from a customer of ISP 'A' can reach a customer of ISP 'B' through the IXP at which A and B connect their networks. Similarly, a customer of ISP 'B' can access a website hosted by a customer of ISP 'A' because the data can flow swiftly and cost-effectively between the networks of the two ISPs through the connections made at an IXP.


The exchange model below strictly hierarchical model of Internet structure is one in which a small number of global ISP transit operators is at the "top"; a second tier is of national ISP operators; and a third tier consists of local ISPs. At each tier the ISPs are clients of the tier above, as shown in Figure 2. If this hierarchical model were strictly adhered to, traffic between two local ISPs would be forced to transit a national ISP, and traffic between two national ISPs would transit a global ISP, even if both national ISPs operated within the same country. In the worst case, traffic between two local ISPs would need to transit a national ISP, and then a global ISP from one hierarchy, then a second global ISP, and a second national ISP from an adjacent hierarchy in order to reach the other local ISP. If the two global providers interconnect at a remote location, the transit path of the traffic between these two local ISPs could be very long indeed. As noted above, such extended paths are inefficient and costly, and such costs are ultimately part of the cost component of the price of Internet access. In an open competitive market, strong pressure always is applied to reduce costs. Within a hierarchical ISP environment, strong pressure is applied for the two national providers, who operate within the same market domain, to modify this strict hierarchy and directly interconnect their networks. Such a local interconnection allows the two networks to service their mutual connectivity requirements without payment of transit costs to their respective global transit ISP providers. At the local level is a similar incentive for the local ISPs to reduce their cost base, and a local interconnection with other local ISPs would allow local traffic to be exchanged without the payment of transit costs to the respective transit providers.


Why Do IXPs Matter? 


IXPs are among the most critical elements in the infrastructure of the Internet.  The Internet is a network of interconnected networks;  IXPs are the points at which multiple networks interconnect.  Without IXPs, there would be no Internet, as we have come to know it. In more concrete terms, IXPs generate two primary advantages for member ISPs and their customers:  lower costs and improved quality of service. 


Cost Advantages Currently, nearly all developing countries lack IXPs, meaning that all inter-ISP traffic (both domestic- and foreign-bound) must be exchanged through exchanges outside the country. Absent a domestic IXP, then, an ISP must send all outbound traffic through its international links, most commonly satellite and occasionally submarine fiber. International links entail both upstream and downstream packet traffic, the costs of which must be borne by either the sending or the receiving ISP.  Here, we observe a troubling imbalance:  Unlike in the telephony world, where ITU-mandated rules require that the costs of international calls be shared 50/50 between telecom operators, international Internet connectivity operates according to the peering/transit dichotomy.  ISPs are not subject to the ITU's cost-sharing rules; rather, connectivity costs are allocated according to bilateral contracts, which can generally be classified as either peering or transit agreements. 


The distinction is significant:


1. Peering

A peering agreement is a bilateral business and technical arrangement in which two connectivity providers agree to accept traffic from one another (and from one another's customers, and their customers' customers).  In a peering agreement, there is no obligation for the peer to carry traffic to third parties.  There are no cash payments involved – rather, it is more like barter, with each ISP trading direct connectivity to its customers in exchange for connectivity to the ISP's customers.


2. Transit

A transit agreement is also a bilateral business and technical arrangement, but one in which the transit provider agrees to carry traffic from the customer to third parties, and from third parties to the customer.  The customer ISP is thus regarded as an end point for the traffic; the transit provider serves as a conduit to the global Internet.  Generally, the transit provider will undertake to carry traffic not only to/from its other customers but to/from every destination on the Internet.  Transit agreements typically involve a defined price for access to the entire Internet. For virtually all developing country ISPs, the only option for connectivity to the global Internet is a transit agreement.  That is, a given developing country ISP has such a small customer base that the international Tier-1 and Tier-2 providers have no business incentive to enter a shared-cost peering agreement with it.  Instead, the developing country ISP must sign a transit agreement with its upstream provider. The result (to oversimplify slightly) is that developing country ISPs must pay 100% of both outbound and inbound traffic;  under the terms of the transit agreement, the ISP on the other end of the international link does not share the cost of exchanged traffic.  This means that the developing country ISP must pay 100% of the international transit costs for all packet traffic (email, web pages, file transfers, etc.) that originates with its customers and that terminates with its customers.  In other words, if the customer of a Afghan ISP sends an email to a friend in the United States, the Afghan ISP bears the full cost of the packets' outbound transmission over its international link.  Neither the recipient's ISP nor intermediate upstream carriers bear any of the transit cost.  If the friend in the United States sends an email reply back to Afghanistan, the Afghan ISP must again bear the full cost of inbound transmission over its international link.


Quality of Service Advantages


Due to the lack of fiber optic links, most developing country ISPs use VSAT satellite circuits for international connectivity to upstream ISPs.  Satellite connections introduce significant latency (delay) in the network.  More problematic is the reality that, without an IXP, even domestic traffic must be exchanged internationally, entailing at least two satellite hops. (Indeed, even were hard fiber connections available, the length of transatlantic cables introduces needless (though much smaller) latency in the connection.) Significant network latency translates into extremely slow connections for users, putting a tremendous range of Internet services out of practical reach.  Local Internet enterprises find themselves at an inherent disadvantage if they attempt to serve international customers. Ironically, they find themselves at a double disadvantage in serving domestic customers, whose queries must traverse at least two satellite hops to reach them, and another two satellite hops to receive the response.  Forcing local ISPs to interconnect in another country thus places a major obstacle to the development of domestic Internet-based business.  Indeed, many and perhaps most developing country Internet services are hosted on servers in the United States or Europe, to eliminate at least one satellite hop out of each transaction (including domestic).


Making the problem worse, nearly every developing country is experiencing rapidly growing demand for Internet connectivity, with ISPs offering faster local connections and users requiring greater volumes and more bandwidth-intensive types of Internet services.  The growth in demand places ever-increasing burdens on the transmission capabilities of ISPs, whose provisioning of bandwidth must keep pace.  In many cases, ISPs use their transmission lines at100% of capacity, resulting in dropped transmission of packets of data, re-transmissions of dropped packets, and a resulting compounded latency for completing Internet transactions. 


An IXP slashes network latency by eliminating the need for any satellite hops in the routing of domestic-bound traffic.  The result is that more customers use domestic Internet services, increasing local demand for bandwidth and prompting a cycle in whichever more bandwidth is dedicated to local interconnection.  Since domestic bandwidth is always cheaper than international bandwidth, the business cases for domestic Internet enterprises improve dramatically 

• Not just for ISPs, but for online banking, e-commerce sites, online government, enterprise VPNs, content hosting, web services, etc. Regardless of the medium, then, a closer connection will be cheaper, faster, and more efficient.  Put another way, the localization of packet traffic; 

• Keeping the physical path traversed by packets as short as possible; 

• Produces measurable improvements in service cost, performance, and efficiency;



Types of EPs


Exchange points typically include a data link (layer 2) connectivity service, such as a switch or hub of some type. It is also possible for the EP to include a router, which imports routes from ISPs and announces them back out to the participants. In this case the EP operator is a hybrid ISP, EP types identified in the tables include:


• Ethernet: ISP routers connect in a single geographic location using an Ethernet hub, switch, or switch fabric that supports Ethernet framing.

• FDDI: ISP routers connect in a single location using an FDDI concentrator or switch. Note that Ethernet and FDDI LANs within EPs are typically bridged to allow peering between any two ISPs regardless of attachment type.

• Wide area Ethernet or FDDI: ISPs use wide area LAN bridging to reach the EP.

• ATM: ISP routers connect via ATM PVCs over a metropolitan or national ATM switch or backbone. Note that ATM, FR, and SMDS networks cannot be bridged to communicate transparently with Ethernet or FDDI. For example, the FDDI ring and ATM switch at the Pacific Bell NAP are essentially two separate and unconnected infrastructures.

• FR: ISP routers connect via Frame Relay PVCs over a metropolitan or national FR service.

• SMDS: ISP routers connect via Switched Multimegabit Data Services over a metropolitan or national SMDS service.

• Router: A router may be operated by the EP manager. This router may act as a route server, collecting routing information from the peers, and re-announcing these routes back to each peer. A Multi-Lateral Peering Agreement with full participation can be implemented this way.

• Physical level interconnect: ISP servers and routers may be connected to each other, and to equipment owned by other collocated ISPs, and attached to a selection of local and long distance carriers. DS3 and SONET services provide a scalable method of interconnection for ISPs using this type of exchange point.





Connection policy


Rules and policy for connection to EP, and any applicable rules for routing or connections to other EP participants. Also whether transit is available at this EP.


The purpose of the National Internet Exchange of Afghanistan (NIXA) shall be to encourage the exchange of Internet traffic in a free-market environment, between all interested parties.  By locating an Internet exchange in Kabul, near the majority of Afghanistan's Internet Service Providers and large Internet users, competition will be spurred, consumer prices will drop, operational costs will be reduced, reliability and redundancy will be improved, and a vast amount of new local Internet bandwidth will be created for sale to consumers.


The National Internet Exchange of Afghanistan (NIXA) is recognized to be in the beneficial interest of all stakeholders.  


General National Internet Exchange of Afghanistan (NIXA) technical, business, and operational policies shall be made publicly available on the NIXA web site.


The NIXA shall never impose a mandatory fee upon any member, nor shall it bill any such fee on behalf of another party.  Furthermore, no monies shall ever flow between members through the NIXA corporation.  Any costs (currently foreseen to include only property insurance and electricity) shall be met through the voluntary donations of any party, whether member or non-member, and donating parties shall be encouraged to donate according to their means, but not in excess of the NIXA’s present need. The NIXA board shall endeavor to operate the exchange in a manner which insures a fairness of the value to each member.


The NIXA shall not endeavor to act as a go-between, point of aggregation, or distributor of regulatory or licensing burden among its members.


The NIXA shall attempt to make resources available to members in accordance with need.  Specifically, the NIXA shall allocate switch ports to members based upon estimate or evidence of each member’s relative ability to fill the port with beneficial traffic.  In priority, ports shall be allocated to new members before second or additional ports are allocated to existing members.  Colocation space for members' routers in the NIXA -maintained racks shall be limited to per member, and shall be allocated strictly on an as-needed basis.


The NIXA shall impose no restriction upon the types of organization or individual who may become members and connect to the exchange.


The NIXA shall impose no restrictions upon the internal technical, business, or operational policies of its members.


The NIXA shall make no policy and establish no restrictions upon the bilateral or multilateral relationships or transactions which the members may form between each other, so long as the NIXA corporation shall not be involved.


The NIXA shall collect and make aggregate traffic statistics public on the NIXA web site.


The NIXA shall maintain reasonable security, both physical and network, regarding the switch, route reflectors, and members' interconnections with them.


Members shall be encouraged, but not required, to establish BGP peering sessions with one route reflector, which shall be operated as a publicly-visible "looking glass."  Members shall be required to establish a BGP peering session and advertise all customer routes to the other route reflector, which shall be operated with respect for the privacy of members' routing information, but is necessary for the safe and reliable operation of the exchange, and the diagnosis and correction of exchange operational problems.


Members shall be required to sign a copy of the NIXA policies document, indicating that they understand and agree to abide by its policies, before any resources shall be allocated to them.


Members shall be required to provide and maintain current technical contact information, which shall be publicly posted on the NIXA web site. This information shall include at a minimum an internationally-dialable voice phone number, a NOC email role account, the IP address assigned to the member at the exchange, and the member's Autonomous System Number if they have one.


Members shall subscribe to a NIXA announcement email list, operated by the NIXA board.


Members have a duty of confidentiality to each other regarding NIXA affairs or information learned in the course of NIXA operation.  This applies particularly to the NIXA board.


Members shall under no circumstances refer non-members to the NIXA board for resolution of technical problems.


Members shall endeavor to provide advance notice via email to each of their BGP peers, in the event that a service disruption or discontinuity of BGP peering can be foreseen.


Members may only connect equipment which they own and operate themselves to the NIXA.  They may not connect equipment on behalf of third parties.


Members shall not advertise routes other than their own, without the prior written permission of the assigned holder of the address space.


Members shall not advertise a next-hop other than their own.


Members must, on all interfaces connected to the NIXA switch fabric, disable Proxy ARP, ICMP redirect, CDP, IRDP, directed broadcasts, IEEE802 Spanning Tree, any interior routing protocol broadcasts, and any MAC layer broadcasts other than ARP or inverse-ARP.


Members must, on all interfaces connected to the NIXA switch fabric, disable any duplex, speed, or other link parameter auto-sensing.


Members must set netmasks on all interfaces connected to the NIXA to include the entire NIXA peering LAN.


Members must clearly label all equipment which resides at the NIXA facility with ownership and contact information.


Members should not routinely use the NIXA switch fabric for carrying traffic between their own routers.






In order to address the issue of sustainability in long run, NIXA shall setup minimum amount of fee on peering ISPs for covering the recurring costs of NIXA




NIXA will be monitored with the required available tools and equipments for providing routine statistics on the performance of EP, which will be available on the NIXA website.


Details of Exchange Point


Exchange Point


National Internet Exchange of Afghanistan (NIXA)



Kabul Afghanistan

Web Site


Connection type


Physical interfaces supported



ISP Association of Afghanistan / Observers from Govt


Next Steps

Following are some of the activities for establishment of NIXA:

• Meeting with local ISPs

• Procurement of required equipments for IX main hub ( ICT Project completed)

• Providing initial training for management of IX and peering ISPs ( PCH ready )

• Discussing sustainability issue of IXP with stakeholders