IPX and GRX

IPX : Don't worry it is not the old IPX LAN protocol we all dreaded about, IPX is a GSMA standard for interconnecting mobile operators ( MNO). GRX was predecessor for IPX and the big difference between IPX and GRX is that GRX let only MNO to be interconnected. IPX extends this to interconnect ASP and Content providers as well. As part of this they have introduced QOS and provided guidelines as what to expect in terms of latency between endpoints.  

SO what is IPX technically for people who understand IP network ?, it is nothing more than a private IP network. It could be either a MPLS VPN from a carrier or an organizations own optical network with specific QOS and Latency requirements.

There are few IPX network operators, some of them are Syniverse, BIC's , Acision etc...

One other important restriction in IPX in it is not allowed for more than two IPX operator to daisy chain, in other words only operators having customers could connect and there cant be transit IPX providers.

reason for establishing GRX and IPX was mainly to reduce the N^2 connectivity issue between operators when they roam.

More information on IPX:

http://www.gsmworld.com/our-work/programmes-and-initiatives/ip-networking/ip_exchange.htm