Live trading session from Disaster Recovery site

National Stock Exchange of India Limited

Circular

All Members,

Live trading session from Disaster Recovery (DR) site

This is in reference to Exchange Circular no. NSE/MSD/44692 dated June 18, 2020 regarding Unannounced live trading sessions from Disaster Recovery (DR) Site.

Members are requested to note that Exchange shall be conducting live trading/bidding session from its Disaster Recovery (DR) as per below:

Important instructions for members:

• For connecting to Primary/DR site, no changes in NEAT Adapter settings are required.
• BCP LIVE trading is being conducted for Equity, Equity Derivatives, Currency Derivatives, Commodity Derivatives, SLB, EGR segments. In case of web-based platform (eIPO, eOFS, CBRICS and RFQ, EBP, NDM - Order Matching Platform, Negotiated Trade Reporting Platform & Tri-Party Repo Market Platform ) existing URL shall be used for - Live bidding session login from Primary/DR site.
• Refer to Exchange circular download ref no NSE/MSD/73993 dated April 30, 2026 & NSE/MSD/74511 dated June 02, 2026 for Interactive Connectivity Parameters.
• Lease-line members are requested to connect to below mentioned IP address for Extranet.
  • Extranet - https://172.19.125.70/extranet-api/
  • C2N-172.19.125.70
• Co-location facility and Multicast Tick by Tick (MTBT) feed shall be available. MTBT feed will be available on the same Production IP's.
• In Live trading session conducted from DR site, orders from colocation shall be routed from the main site to the BCP site. Similarly the dissemination shall be done from the BCP/DR site to the colocation racks in the main site.
• Latencies experienced by Colo Participants will be different on Disaster Recovery/BCP day as compared to a normal trading day.
• Further updates with respect to live trading session, if any shall be intimated separately.

In case of queries members may reach out to the below mentioned toll free numbers.

For and on behalf of
National Stock Exchange of India Limited

Khushal Shah
Associate Vice President

Annexure – 1

Advisory for members subscribing to Multicast Tick By Tick Feeds (MTBT)

• Kindly note that the MTBT data broadcast being on UDP, there can be occasional drops in the broadcasts provided by the Exchange due to the same. It is an expected behaviour.
• If any such packet loss observed for MTBT broadcasts, members can request to fetch the missed packet through TBT Recovery mechanisms in place.
• Members are requested to refer the API’s for MTBT, wherein we have provided the tuning parameter for receiving MTBT as well as guidelines for recovery.
• As mentioned in the API, the Tick Data feed is available on two separate Multicast Channels (Source 1 and Source 2) for each Stream on active-active basis. On one multicast channel the feed is delayed and lagging behind the other feed. Please refer the circular no. 75324 dated July 21, 2026, & 74019 dated April 30, 2026 for details regarding the Source 1 and Source 2 multicast IP and port.
• It is recommended that the end user application should subscribe to both multicast channels for each stream and receives the data from both the channels in active-active manner. This needs to be done to ensure that data loss is minimized for the receiving applications as there is a possibility of data loss in multicast protocol.
• If the end user application misses any tick data from both the active-active channels it can recover the ticks by sending recovery requests to recovery server on TCP. The recovery requests are served from file stored in recovery server. Due to this factor, there is a lag / delay in the tick data from recovery servers, as compared to direct multicast feed