diff --git a/experimental/src/compute/mod.rs b/experimental/src/compute/mod.rs
index b5f3b7d27..e0958e5e1 100644
--- a/experimental/src/compute/mod.rs
+++ b/experimental/src/compute/mod.rs
@@ -1,5 +1,6 @@
 pub mod ast;
 pub mod lexer;
+pub mod threshold;
 
 use self::ast::ExprResult;
 use self::lexer::{LexicalError, Tok};
diff --git a/experimental/src/compute/threshold.rs b/experimental/src/compute/threshold.rs
new file mode 100644
index 000000000..2d55822aa
--- /dev/null
+++ b/experimental/src/compute/threshold.rs
@@ -0,0 +1,105 @@
+use std::f64::INFINITY;
+
+use log::{debug, error, info, trace, warn};
+
+pub struct Threshold {
+    start: f64,
+    end: f64,
+}
+
+impl Threshold {
+    pub fn parse(expr: &str) -> Threshold {
+        // https://nagios-plugins.org/doc/guidelines.html#THRESHOLDFORMAT
+        let mut start: usize = 0;
+        let mut in_number = false;
+        let mut start_value = -INFINITY;
+        let mut end_value = INFINITY;
+        let mut in_range = false;
+        for (idx, c) in expr.char_indices() {
+            if in_number {
+                match c {
+                    '0'..='9' => continue,
+                    '.' | '-' | '+' | 'e' | 'E' => continue,
+                    _ => {
+                        in_number = false;
+                        start_value = match expr[start..idx].parse() {
+                            Ok(x) => x,
+                            Err(err) => {
+                                error!("parse error: {}", err);
+                                std::process::exit(3);
+                            }
+                        }
+                    }
+                }
+            }
+            /* No else here, because we can continue the previous match */
+            if !in_number {
+                match c {
+                    ' ' => continue,
+                    '0'..='9' => {
+                        in_number = true;
+                        start = idx;
+                    }
+                    ':' => {
+                        in_range = true;
+                    }
+                    _ => break,
+                }
+            }
+        }
+        if in_number {
+            start_value = match expr[start..].parse() {
+                Ok(x) => x,
+                Err(err) => {
+                    error!("parse error: {}", err);
+                    std::process::exit(3);
+                }
+            }
+        }
+
+        /* We have noticed a ':' character, so the threshold is a range */
+        if in_range {
+            return Threshold {
+                start: start_value,
+                end: INFINITY,
+            };
+        } else {
+            return Threshold {
+                start: 0_f64,
+                end: start_value,
+            };
+        }
+    }
+
+    fn in_alert(&self, value: f64) -> bool {
+        if value < self.start || value > self.end {
+            return true;
+        }
+        false
+    }
+}
+
+mod Test {
+    use super::*;
+
+    #[test]
+    fn test_parse_value() {
+        let expr = "1.2";
+        let threshold = Threshold::parse(expr);
+        assert_eq!(threshold.start, 0_f64);
+        assert_eq!(threshold.end, 1.2_f64);
+        assert!(threshold.in_alert(2_f64));
+        assert!(threshold.in_alert(-1_f64));
+    }
+
+    #[test]
+    fn test_parse_val_colon() {
+        let expr = "10:";
+        let threshold = Threshold::parse(expr);
+        assert_eq!(threshold.start, 10_f64);
+        assert_eq!(threshold.end, INFINITY);
+        assert!(!threshold.in_alert(10_f64));
+        assert!(!threshold.in_alert(11_f64));
+        assert!(threshold.in_alert(9_f64));
+    }
+}
diff --git a/experimental/src/generic/mod.rs b/experimental/src/generic/mod.rs
index e542d11df..63147ae22 100644
--- a/experimental/src/generic/mod.rs
+++ b/experimental/src/generic/mod.rs
@@ -1,7 +1,7 @@
 extern crate serde;
 extern crate serde_json;
 
-use compute::{ast::ExprResult, Compute, Parser};
+use compute::{ast::ExprResult, threshold::Threshold, Compute, Parser};
 use log::{debug, trace};
 use serde::Deserialize;
 use snmp::{snmp_bulk_get, snmp_bulk_walk, snmp_bulk_walk_with_labels};
@@ -10,11 +10,13 @@ use std::{collections::HashMap, ops::IndexMut};
 use crate::snmp::SnmpResult;
 
 #[derive(Debug)]
-struct Perfdata {
+struct Perfdata<'p> {
     name: String,
     value: f64,
     min: Option<f64>,
     max: Option<f64>,
+    warning: Option<&'p str>,
+    critical: Option<&'p str>,
 }
 
 #[derive(Copy, Clone, PartialEq)]
@@ -219,11 +221,22 @@ impl Command {
                                 panic!("A label must be a string");
                             }
                         };
+                        let status = compute_status(*item, &metric.warning, &metric.critical);
+                        let w = match metric.warning {
+                            Some(ref w) => Some(w.as_str()),
+                            None => None,
+                        };
+                        let c = match metric.critical {
+                            Some(ref c) => Some(c.as_str()),
+                            None => None,
+                        };
                         let m = Perfdata {
                             name,
                             value: *item,
                             min: compute_threshold(i, &min),
                             max: compute_threshold(i, &max),
+                            warning: w,
+                            critical: c,
                         };
                         trace!("New metric '{}' with value {:?}", m.name, m.value);
                         metrics.push(m);
@@ -240,11 +253,22 @@ impl Command {
                             res
                         }
                     };
+                    let status = compute_status(*s, &metric.warning, &metric.critical);
+                    let w = match metric.warning {
+                        Some(ref w) => Some(w.as_str()),
+                        None => None,
+                    };
+                    let c = match metric.critical {
+                        Some(ref c) => Some(c.as_str()),
+                        None => None,
+                    };
                     let m = Perfdata {
                         name,
                         value: *s,
                         min: compute_threshold(0, &min),
                         max: compute_threshold(0, &max),
+                        warning: w,
+                        critical: c,
                     };
                     trace!("New metric '{}' with value {:?}", m.name, m.value);
                     metrics.push(m);
@@ -304,11 +328,22 @@ impl Command {
                                     res
                                 }
                             };
+                            let status = compute_status(item, &metric.warning, &metric.critical);
+                            let w = match metric.warning {
+                                Some(ref w) => Some(w.as_str()),
+                                None => None,
+                            };
+                            let c = match metric.critical {
+                                Some(ref c) => Some(c.as_str()),
+                                None => None,
+                            };
                             let m = Perfdata {
                                 name,
                                 value: item,
                                 min,
                                 max,
+                                warning: w,
+                                critical: c,
                             };
                             trace!("New metric '{}' with value {:?}", m.name, m.value);
                             metrics.push(m);
@@ -316,11 +351,22 @@ impl Command {
                     }
                     ExprResult::Number(s) => {
                         let name = &metric.name;
+                        let status = compute_status(s, &metric.warning, &metric.critical);
+                        let w = match metric.warning {
+                            Some(ref w) => Some(w.as_str()),
+                            None => None,
+                        };
+                        let c = match metric.critical {
+                            Some(ref c) => Some(c.as_str()),
+                            None => None,
+                        };
                         let m = Perfdata {
                             name: name.to_string(),
                             value: s,
                             min,
                             max,
+                            warning: w,
+                            critical: c,
                         };
                         trace!("New metric '{}' with value {:?}", m.name, m.value);
                         metrics.push(m);