Revenue - Disaggregation of revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Revenue
Revenue	$ 52,790	$ 52,277	$ 105,237	$ 103,052
Percent of Total	100.00%	100.00%	100.00%
Products and Licenses transferred at a point in time
Revenue
Revenue	$ 28,731	$ 28,378	$ 58,216	56,823
Services transferred over time
Revenue
Revenue	24,059	23,899	47,021	46,229
Europe, Middle East, Africa (EMEA) [Member]
Revenue
Revenue	$ 23,521	$ 24,830	$ 48,397	$ 51,819
Percent of Total	44.00%	47.00%	46.00%	50.00%
Americas
Revenue
Revenue	$ 19,329	$ 17,011	$ 36,578	$ 33,539
Percent of Total	37.00%	33.00%	35.00%	33.00%
Asia Pacific [Member]
Revenue
Revenue	$ 9,940	$ 10,436	$ 20,262	$ 17,694
Percent of Total	19.00%	20.00%	19.00%	17.00%
Hardware products
Revenue
Revenue	$ 18,783	$ 19,451	$ 34,134	$ 37,119
Software licenses
Revenue
Percent of Total	6.00%		6.00%
Subscription
Revenue
Revenue	$ 19,829	15,746	$ 43,098	32,128
Professional services
Revenue
Revenue	$ 2,000	4,046	$ 3,881	8,248
Percent of Total	2.00%		2.00%
Maintenance, support and other
Revenue
Revenue	$ 12,178	$ 13,034	$ 24,124	$ 25,557