Railnet Network Extension using 4 G LTE Router at

Remote Location

Pramod Kumar, CCE, HJP, East Coast RailwayRavi Prakash, SSE(Tele), HJP, East Coast Railway

Abstract

Introduction of various e services on Railnet like eof-fice, eDAS, IP-telephony, Video Conferencing, cre-ation of our own Cloud for sharing of informationfrom Any where/Any time etc. and much more em-phasis on digitalization/paperless working in day today Railway office working has given Railnet vitalimportance and its availability anywhere and every-where has becomes paramount.This article discussesa scheme to extend the Railnet to remote locationon readily available LTE network of various telecomservice providers with 4G LTE Router. It also doc-uments the trials done in ECR and the learning de-rived from this trial.

1 Intruduction

On Indian Railway, Railnet is a pan india networkand has been provided in Railway Board, Zonal Hq,Divisional Hq, and other important premises andstations over the Railway jurisdiction. Railnet isvital for running applications such as eoffice, eDas,HMIS etc. Therefore, 100 % availability of Railnetat desired locations is the foremost priority of S&Tdepartment. Now people are working from home dueto COVID-19. Railway officials can work throughe office from home with the expansion of Railnet,.The physical and geographical line has been blurrednow. The Railnet Network can easily be extendedto the remote locations by using 4G LTE SIM basedrouter for seamless work from any remote locations.

2 Basic Building blocks for theset up of Railnet extension

(i) VPN system in Railnet network atZonal/Divisional Headquarter.

(ii) 01 No of 4G LTE Router at remote locations.

(iii) 01 No SIM cards (CUG).

(iv) 230 stable AC power supply at remote location.

3 VPN system Set up at Divi-sional/Zonal HQ

(i) A VPN (virtual private network) is a servicethat creates a safe, encrypted online connec-tion. VPNs essentially extend a private net-work across a public network, which should al-low a user to securely send and receive dataacross the internet. VPN tunneling creates apoint-to-point connection that cannot be ac-cessed by unauthorized users. To create thetunnel, a tunneling protocol is used over ex-isting networks. Different VPNs will use dif-ferent tunneling protocols, such as OpenVPNor Secure Socket Tunneling Protocol (SSTP).The tunneling protocol used may depend onthe platform the VPN is being used on, suchas SSTP being used on Windows OS, and willprovide data encryption at varying strengths.The endpoint device needs to be running a VPNclient (software application) locally or in thecloud.

(ii) For VPN setup a VPN router should be in-stalled and a public IP will be configured toits one of the ethernet port and other Ether-net port will be connected to our local RailnetLAN. The client software or configuration maybe done in the local PC/Laptop. The setupblock Diagram is give below(Figure 1):

At Divisional/Zonal Office, VPN system with L2TP/Open VPN Protocol should be configured andintegrated and with Railnet network.

Figure 1: VPN system Set up at Divisional/ZonalHQ

4 VPN system Set up at Re-mote location

ECR HQ Hajipur is already having a VPN Routerwith L2TP Protocol configured on it . Public IPwhich has been taken from RCIL is configured onL2TP server application on VPN router . D-LinkDWR-921 4G Router in Remote location is used forestablishing the internet connectivity using a Airtel4 G SIM card on its 1st WAN port interface. Thenwe have configured 1 more WAN interface as L2TPover IPSec using L2TP server details configured onVPN router at Divisional/Zonal office. After thatL2TP WAN interface of 4G Router will receive IPaddress, subnet mask, Gateway & DNS server formL2TP server of VPN router at Divisional/Zonal of-fice. After this we have added static Route in D-LinkDWR-921 4G Router for accessing Railnet LAN net-work (10.0.0.0/8). After configuring this static routein remote end router, PC connected with 4G routerLAN can directly access the remote Railnet networkand Applications.

Figure 2: Schematic Plan of the entire set up

5 Step by Step configuration isas follows:

(i) Router LAN configuration: First the routerwill be accessed through web browser using theLocal IP address of the LTE router.

Figure 3: Schematic Plan of the entire set up

(ii) IP details of Laptop connected to LAN port ofthe Router:

Figure 4: Schematic Plan of the entire set up

(iii) Router WAN configuration with LTE forInternet: The WAN port of the LTE routershould be configured for APN as per SIM con-figuration for internet.

Figure 5:

Figure 6:

Figure 7:

(iv) One more WAN interface configurationfor L2TP over IPSec: After configuratingthe remote router for internet on one of itsWAN interface.We added one more WAN inter-face of the LTE router for L2TP protocol. Weselect connection type as L2TP over IPSec andthe put the details received from VPN routerat divisional/Zonal.

Figure 8:

Figure 9:

Figure 10:

Figure 11:

(v) Device WAN Status:

Figure 12:

Figure 13:

Figure 14:

(vi) Routing Settings: To reach the remote net-work of Railway (10.0.0.0/8) from the Router’sLAN network (192.168.0.0/24) we need to addthe static route with L2TP WAN interface &its IP address as gateway.

Figure 15:

Figure 16:

(vii) Reachability Status for the Remote LANnetwork.

Ping & Trace Route to 10.169.250.150

Figure 17:

(viii) Ping & Trace Route to 10.0.224.5

Figure 18:

(ix) Local breakout for internet traffic and itpasses via local gateway and do not goover L2TP Tunnel

Ping & Trace route to global DNS 8.8.8.8

Figure 19:

(x) Railway’s Application access for RemoteLAN network PC:

Figure 20:

Figure 21:

6 Trail Result

By using the 4g LTE SIM based router the Rail-net is successfully extended at the remote loca-tion. The speed was dependent on the band-width of the service provider network. But it isgood enough for normal application like eoffice,e Das, voice telephony, HMIS etc.

7 Conclusion & Way Ahead

From the trials the following conclusions can bedrawn.

(i) The scheme of extending the Railnet Net-work through 4G LTE SIM based routeris technically feasible.

(ii) Stable power supply (may be using UPS)at remote location is required to powerthe 4G Router.

(iii) Once the system stabilizes, it can be usedto extend the UTS/PRS/FOIS Networkat remote locations with proper VPN in-stallation with UTS/PRS/FOIS system.

(iv) The system may be used in ART for pro-viding the Railway Telephone and Railnetat the site.

(v) Multisim based 4G router can be exploredwhere bandwidth of various sims can becombined for higher bandwidth applica-tion.

Shri Pramod Kumar isan IRSSE officer of 2001batch. He started his careeras ASTE Mumbai subur-ban and has worked exten-sively in Operation &Main-tenance under open line invarious capacities as ASTE,DSTE and Sr DSTE onWRand ECR. He also has a vastexperience of design, development, execution andmanagement of projects under new line, doubling,gauge conversion and railway electrification whileworking as Dy CSTE on ECR and CORE. Presently,he is working as CCE /ECR and is closely associatedwith faster roll out of IP based VSS, VOIP basedTCCS, IP MPLS and LTE on ECR.

Shri Ravi Prakash is aMaster of Science with In-formation technology as thespecialization. He has ex-perience of 21 years in In-dian Railways. He is expe-rienced in the field of Mi-crowave, Quad, OFC in-stallation, Wireless System,CCTV and Data network ofIndian Railways. He has commissioned Exchanges atECR. He is instrumental in implementation of HMISover ECR He is also experience in radio planningto protect control and other E1’s required for en-hancing the control communication uptime. He alsoholds good knowledge of TDM and Asterisk VoIPexchange, VoIP based TCCS, IP-MPLS System, IPbased CCTV system. Presently he is working asSSE/Tele at headquarter Hajipur/East Central Rail-way.