Experiencing slow response times against both production and test APIs

[anthonynowak]

We have been getting reports of slow responses on our websites which hook into the authnet sdk for payments.  weve tracked it down to each call out to the API takes 15-30 seconds to respond.  We are on an older version of the SDK but ive loaded the latest and greatest and still the same delay.  This is for any request related to AIM and ARB.

running Centos 7 using php 5.6 - anyone else seeing the same?  Not sure when this started but first reports started coming in a couple weeks ago.

[anthonynowak]

added some curl verbose output and seems to be on the api end being the http connection was already made unless im mistaken

there was an 18 second pause between "* upload completely sent off: 214 out of 214 bytes" and "< HTTP/1.1 200 OK"

* About to connect() to test.authorize.net port 443 (#0)
* Trying 69.192.141.182...
* Connected to test.authorize.net (69.192.141.182) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* CAfile: /home/anowak/authnet/sdk-php/lib/ssl/cert.pem
CApath: none
* SSL connection using TLS_RSA_WITH_AES_256_CBC_SHA
* Server certificate:
* subject: CN=test.authorize.net,OU=Operations,O=Authorize.Net LLC,L=American Fork,ST=Utah,C=US
* start date: Apr 15 15:45:10 2015 GMT
* expire date: Apr 17 18:26:49 2016 GMT
* common name: test.authorize.net
* issuer: CN=GeoTrust SSL CA - G4,O=GeoTrust Inc.,C=US
> POST /gateway/transact.dll HTTP/1.1
Host: test.authorize.net
Accept: */*
Content-Length: 214
Content-Type: application/x-www-form-urlencoded

* upload completely sent off: 214 out of 214 bytes

< HTTP/1.1 200 OK
< Cache-Control: private, must-revalidate, max-age=0
< Content-Type: text/html
< Expires: Tue, 01 Jan 1980 00:00:00 GMT
< Server: Microsoft-IIS/7.5
< X-Powered-By: ASP.NET
< X-Cnection: close
< X-Akamai-Transformed: 9 325 0 pmb=mRUM,1
< Date: Mon, 08 Jun 2015 21:22:15 GMT
< Content-Length: 325
< Connection: keep-alive
<
* Connection #0 to host test.authorize.net left intact