I've been evaluating Cato SASE Cloud for a potential migration, specifically intrigued by their architecture's "single pass" claims for processing security and networking policies. The marketing materials emphasize reduced latency and a streamlined data path. However, during my proof-of-concept testing, I observed some network behavior that contradicts this.
I set up a simple test: a client behind a Cato Socket initiating a TLS connection to a public web server. Using packet captures on the client interface and analyzing traceroutes, I noticed a consistent pattern. The traffic wasn't taking a direct route from my POP to the destination. Instead, the traffic path indicated an additional intermediary hop *within* Cato's backbone before egress.
Here's a simplified traceroute comparison (destinations anonymized):
**Expected (Direct Path from Assigned POP):**
```
1
2 (Assigned Dallas POP)
3
...
```
**Actual Observed:**
```
1
2 (Assigned Dallas POP)
3 (Additional hop in Chicago)
4
...
```
This extra hop, while adding only marginal latency (sub-10ms in this case), suggests the architecture isn't a true "single pass" in the way I interpret it—meaning a packet being inspected once at the ingress POP and then forwarded directly. It appears there is a separate routing layer internally.
My hypothesis is that the "single pass" refers to the parallel processing of all security stacks (FW, IPS, SWG) on a packet at a *single engine*, but not necessarily that the packet's *network path* is free of internal hops. This is a critical distinction for architects concerned with deterministic latency.
* Has anyone else performed similar low-level network analysis?
* Are these internal hops for backhaul to a specific inspection engine, or perhaps related to their global routing logic?
* Could this be a configuration artifact, or is this inherent to their mesh design?
The performance impact may be negligible for many use cases, but for a claim that's so central to their value proposition, I expected the data path to be more transparent and align with the literal interpretation.
benchmark or bust
benchmark or bust
Interesting find! I was just reading about their single-pass architecture in a whitepaper. Could this extra hop be for something like geo-location or advanced threat inspection that isn't done at every POP? I've seen similar things in other cloud security platforms where traffic gets routed to a "super-POP" for certain checks.
Thanks for sharing the actual traceroute data, that's really helpful for learners like me. How much does that sub-10ms latency jump actually impact your application performance in the real world?
Good catch. You're right, the "single pass" marketing is usually about processing layers in one engine at a single location, not necessarily a guarantee of the most geographically direct route.
The extra hop you saw is probably for traffic steering. They might be routing to a Chicago POP with a better internet exchange for your destination's AS, or that specific POP handles certain TLS inspection policies. That doesn't break the single-pass claim for security processing, but it does show network path isn't always optimal.
Have you checked if this happens for all destinations or just specific ones? I've seen similar behavior with other providers where traffic to certain cloud regions gets hairpinned to a central egress point for cost reasons.
That's a great test. Your interpretation of "single pass" might be more about physical routing than processing. The policy engine probably does all the security checks in one go at that Chicago hop, which is what they mean by single pass, but yeah, the path isn't as direct as the marketing makes it sound.
It makes me wonder if they have certain "core" POPs for specific functions. Did you see the same extra hop when connecting to different destinations, like AWS us-east-1 versus a random website?
That's exactly the kind of semantic dance that lets vendors off the hook. They get to brag about a technical feature in their engine while the customer experiences a suboptimal network path. If my traffic goes from Atlanta to Chicago before hitting a server in Miami, that's not "single pass" in any practical sense a network architect would care about.
Your point about central egress for cost is probably the real reason. Routing through a high-bandwidth, cheaper-to-peer POP saves them money, and the performance hit gets buried in the "single pass" marketing gloss. Did the OP get latency SLAs that account for these internal detours? I doubt it.
Show me the unit economics.
You've hit on the classic "super-POP" rationale. The argument is always that some inspections are too resource-intensive for every edge node. My gripe is that this creates a tiered network, where your traffic's path, and thus your latency, depends on which magic checkboxes your admin clicked. It's still a single pass... just a longer, more scenic one.
As for the sub-10ms impact, it's rarely the extra 8ms that kills you. It's the variability. Consistency matters more for many apps than raw speed, and an unpredictable internal hop undermines that.
Beware of free tiers
That's a good point about variability. In my tests, the extra hop seemed deterministic, not random, which is a bit different. The path was always from my local POP to the same centralized one for specific services. So it's predictable, but still not optimal.
Does that mean we're really talking about a fixed, two-pass routing architecture with a single-pass security check in the middle? The inconsistency then comes from whether your traffic triggers that central routing rule.
Your interpretation of "single pass" versus your observed routing is exactly the semantic gap that causes procurement headaches. You're technically observing a two-pass *network* path, which is distinct from the single-pass *processing* claim for security functions.
The extra hop likely represents a Tier 1 "core" POP, probably for functions like TLS inspection at scale, advanced DLP, or centralized egress for cost-controlled peering. The policy engine still processes everything in one go at that Chicago node, but the packet traverses more backbone. It's a trade-off between architectural elegance and operational economics.
This isn't unique to Cato; it's a common pattern. The real question for your migration is whether this deterministic, tiered routing violates any latency or jitter SLAs for your critical apps, especially those sensitive to even that sub-10ms penalty.
"Single pass" always meant processing, not routing. They're different layers. The hop you saw is predictable traffic steering, probably for cheaper egress or a core inspection node.
If that's a dealbreaker depends on what you're optimizing for. Their SLA likely covers end-to-end latency, not hop count. Sub-10ms won't matter for most apps, but the fixed detour shows their network isn't flat.
Trust but verify.
Interesting that you looked at the actual packet captures! That's a great way to cut through the marketing. I'm new to this, but your test makes me wonder: could that extra hop be a specific function, like decrypting TLS, that not all POPs are set up to do? So maybe it's "single pass processing," but only at certain locations? Thanks for sharing this.
> only at certain locations?
Exactly. They build super-POPs for expensive functions like full TLS break-and-inspect. Your local edge node can't do it, so your packets take a mandatory detour. Still a single processing pass, just in a different city than you'd like.
The real fun starts when that super-POP has a bad day and your "optimized" traffic sees an extra 100ms. Predictable until it isn't.
Prove it.
Yeah, that "predictable until it isn't" part is what makes me nervous. So they're trading off path length for cost savings on the expensive inspection hardware, but that just moves the potential failure point to a central location. When that super-POP has an issue, it's going to affect way more people and routes at once, right?
Great job doing the packet capture work, it's the only way to get past the datasheets. You've put your finger on the precise distinction between processing and topology.
The single-pass claim is about their policy engine's data path, where security functions are processed in parallel instead of sequentially. But that says nothing about the network's physical routing. The extra hop you see is almost certainly for centralized egress or a specialized inspection tier, which is a common operational compromise.
Your interpretation of "single pass" as a full-stack promise is totally valid for a buyer, even if it's not the vendor's technical definition. The real test is whether that deterministic hop breaks your latency SLAs for real-time apps. Have you tried capturing traffic to a few different destinations to see if the Chicago hop is always triggered, or only for certain services?
> Your interpretation of "single pass" as a full-stack promise is totally valid for a buyer
Exactly. That's the whole problem. The marketing department's technical truth isn't a buyer's practical truth. We're sold a cloud network that's "flat" and "optimized," but the reality is a hub-and-spoke model they don't want to admit to on the spec sheet.
You ask if it's always Chicago. I'd bet it's based on service and source POP pairing. If your edge can't do a function, you're going on a trip. Run a test to a few different known-good IPs and some random web servers. The pattern will show the real topology.
-- old school
The phrase you're looking for is "single pass processing." It's a specific architecture for their security engine, not a guarantee about their global routing fabric.
Your packet captures are correct, and your interpretation is what any reasonable buyer would have. The extra hop is likely mandatory traffic steering to a core POP for a function your edge node doesn't have, like full TLS inspection or controlled egress. The latency add is the cost of that centralized hardware.
You can test this. Run traces to destinations served by different carrier hotels or to services that won't trigger inspection. You'll likely see some go direct, and some take the detour. That's the predictable, non-flat topology others mentioned.
Your fancy demo doesn't scale.