Network data from the NetBlocks internet observatory confirm disruptions to mobile networks in Iran on the morning of Wednesday, 25 December. The outage has partial impact and is ongoing at the time of writing. Users report service failures in multiple cities, although the extent of the disruptions has not yet been corroborated.

Network data show two distinct falls in connectivity at approximately 6:30 a.m. local time (03:00 UTC) and 8:00 a.m. (04:30 UTC) affecting mobile provider RighTel, Iran’s third licensed mobile network operator. Severe slowdowns and restrictions to international platforms have been reported with other providers including the leading mobile operators as well as fixed-line networks and are being investigated.

Observations are consistent with a targeted disruption and do not appear to be related to any international issue. Users have speculated a possible connection with anticipated protests on 26 December 2019, which marks the 40th day of mourning for those killed in November.

Update: Mobile internet connectivity has fallen further in #Iran amid reports of security reinforcement; real-time network data show connectivity at 5% of ordinary levels on specified networks after four distinct cuts; incident ongoing 📉#Internet4Iran 📰https://t.co/BNTPP9wEyt pic.twitter.com/Wh2uy5xIxp — NetBlocks.org (@netblocks) December 26, 2019

Background

On December 19, Iran was one of several countries to be affected by an international network failure that also caused widespread disruption to Google services and sparked concerns about intentional blocking.

Update: Internet connectivity in #Iran restored to normal levels after major disruption. Timings match Google platform outages and partial disconnections in nearby countries (see report) pointing to international issue; incident duration ~2 hours 📈 📰https://t.co/FpDRXvB26Y pic.twitter.com/h7nHLXa3WI — NetBlocks.org (@netblocks) December 19, 2019

In November, Iran deliberately shut down internet access amid widespread public protests.

Update: #Iran remains partially offline after reports of intermittent service followed by a sharp decline in connectivity at 21:15 UTC (12:45 am local time); impact visible at national scale affecting multiple networks; incident ongoing #IranProtests 📉 📰https://t.co/1Al0DT8an1 pic.twitter.com/dWKDgAco41 — NetBlocks.org (@netblocks) November 15, 2019

The November disruptions were introduced over a period of 24 hours culminating in a disconnection of all mobile networks followed by a near-total national internet blackout and partial shutdown of telephony services lasting several days.

During that period, access to limited national services became available for some users as part of the country’s national intranet, or National Information Network. Partial connectivity was restored a week after the first outages but mobile networks remained cut for longer and certain regions only regained connectivity weeks later.

Methodology

NetBlocks diffscans, which map the IP address space of a country in real time, show internet connectivity levels and corresponding outages. Purposeful internet outages generally have a distinct network pattern used by NetBlocks to determine and attribute the root cause of an outage, a process known as attribution which follows detection and classification stages.

A summary of data visualizations used in this report:

Network Connectivity by Provider: A subset of internet providers and networks serving the affected region are visualized in a stacked time-series histogram to identify the start and end times of an internet shutdown event. Scales on the y-axis are adjusted to match localized maxima while minima indicate periods when networks became unreachable. The x-axis represents Universal Coordinated time (GMT+0). Standard: Connectivity levels on the y-axis correspond directly to the observed number of reachable connections, as with National Connectivity charts.

A subset of internet providers and networks serving the affected region are visualized in a stacked time-series histogram to identify the start and end times of an internet shutdown event. Scales on the y-axis are adjusted to match localized maxima while minima indicate periods when networks became unreachable. The x-axis represents Universal Coordinated time (GMT+0).

NetBlocks is a civil society group working at the intersection of digital rights, cyber-security and internet governance. Independent and non-partisan, NetBlocks strives for an open and inclusive digital future for all.