If you’re seeing excessive “Time BB Credits Zero” in the gui, or tim_txcrd_z in portstatsshow, you may want to bump up the buffer credits.

{"id":219,"date":"2009-06-24T13:24:21","date_gmt":"2009-06-24T17:24:21","guid":{"rendered":"http:\/\/patrickv.info\/wordpress\/?p=219"},"modified":"2009-06-24T13:24:21","modified_gmt":"2009-06-24T17:24:21","slug":"checking-brocade-ld-bb-credits","status":"publish","type":"post","link":"https:\/\/rootuser.ninja\/index.php\/2009\/06\/24\/checking-brocade-ld-bb-credits\/","title":{"rendered":"Checking Brocade LD BB Credits"},"content":{"rendered":"

If you’re seeing excessive “Time BB Credits Zero” in the gui, or tim_txcrd_z in portstatsshow, you may want to bump up the buffer credits.
\n<\/p>\n

SanSW1:admin> portbuffershow\nUser     Port     Lx           Max\/Resv    Buffer Needed          Link   Remaining\nPort     Type    Mode          Buffers     Usage  Buffers     Distance  Buffers\n----     ----    ----          -------     ------ -------     --------- ----------\n  0              LD              40          0       -             -\n  1              LD              36          0       -             -\n  2        E     LD              60         71      71            25km\n  3              LD              60          0       -             -\n...\n135        F      -               8          8       -             -        413\n----------------------------------------------------------------------------------<\/pre>\n“Max\/Resv Buffers” is the maximum OR reserved buffers allocated to the port, which is adjusted by changing the distance (stupid way to do it) w\/ portCfgLongDistance.<\/p>\n
“Buffer Usage” is the actual number of buffers allocated to the port.  This is affected by the distance set in portCfgLongDistance.<\/p>\n
“Needed Buffers” is the number of buffers that are needed to saturate the link.  If Buffer Usage < Needed Buffers the port will go to \"buffer limited mode\".\n\nIn LD mode the \"Link Distance\" is measured by the round trip time of packets sent and received.\n\n\n<\/p>","protected":false},"excerpt":{"rendered":null,"protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,1],"tags":[],"class_list":["post-219","post","type-post","status-publish","format-standard","hentry","category-san-notes","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/posts\/219","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/comments?post=219"}],"version-history":[{"count":0,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/posts\/219\/revisions"}],"wp:attachment":[{"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/media?parent=219"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/categories?post=219"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/tags?post=219"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}